Update:
I started to like this less and less over the years. Then one day while walking it up, my partner slipped off the ground end. I had passed the center of gravity, so all the weight suddenly pivoted over my head tipping backward. While guiding it to a crash landing on the ground instead of my head, it torqued my shoulder out of the socket. I had to kneel on my hand and reset my shoulder, which is exquisitely painful. It tore up my shoulder cartilage. Now a couple years on, after thousands in medical bills and PT, i wish i had bought a regular extension ladder. Look at what the contractors use... It isn't this. I never use this 26 foot version over about 15-17 feet now.

The specs do say 54 lbs, and so I almost never use the A configuration at lowest levels, because my basic aluminum step ladder is so much easier to get upstairs, into closets, and shelving, around the walls to pain, etc. This 26' model is a beast to use indoors.

What I like:
- The buttons are much improved over the old design. Click, swing the legs apart, they auto-snap into place, done. Easy to hear and see that it's locked.
- The side ratchets are a nice solid design which work very well. Again, you know when they're secure.
- The wide bases make the ladder feel secure, even at full extension
- The number of positions makes it very useful. It's not a gimmick, being able to pose it like gumby makes it incredibly useful

What I don't like:
- It's heavy. This has a solid 20 lbs over a typical extension ladder of similar size.
- Being heavy, it's a bit unwieldy at full extension, and regardless of what the videos show, I like to have a second person holding the base down while I "walk it up". This is of course true of any ladder once you pass the center of gravity, but being heavier, it's just more difficult to control solo. Especially if your neighbor is watching to make sure you don't put it through their window.
- Lacking the traditional rope and pulley of an extension ladder, to get full extension you have to start with one side fully extended, rotate into the straight position, then extend the other side. This looks easy in the video demo with a 17' model. But rotating 27 lbs extended 12 feet over your head is not easy. So, I don't use the video approach, I lay it out across the ground, and have someone stand on one end.

the cons are really just because it's big and heavy, and I got the biggest ladder I could intentionally. however extension ladders are easier to do solo since you're only dealing with half the length initially, and using a rope to pull it up. But for compactness when collapsed, and versatility, this is worth the trade-off to me.

I have had this at one rung shy of full extension up the side of a chimney. There is a bit of bounce to it up that high, but I can't say I ever felt like it was going to fail. The flex isn't distracting. It was a lot more comfortable than standing on the roof.

My take away - If your use case is primarily indoors in the bent configurations, go with the smaller sizes. If you need the reach of a 26 foot ladder and want to use it indoors on occasion, the 26' is ok.

The 12017, owned since May 2012, was a good choice for my specific needs. It is light, and lays flat in the back of my vehicle with one seat down and the tailgate closed. Fully extended, it lands above my second story windows. It feels solid when standing on it as a type 1A (300 pound) should.

It is 14 rungs extended and 4 rungs stored (rungs are 12 inches on center). This wide range is possible because of the center hinge, and because the sections may be extended until only one rung is doubled (overlapped).

The extension locks are easy to use. To release, one squeezes the bottom of the rocking lock lever toward the ladder rail until a ball detent retains the withdrawn lock pin against a spring. The ball detent is just right to hold against the spring, but weak enough to be released by smacking the top of the lever with one's palm. The end of the lock pin is beveled such that one can release the ball detent, then slide the rails until the rungs align enough for the lock pin to spring home. I usually align first, then smack, to reduce wear by the end of the hard steel lock pin rubbing on the aluminum inner ladder rail. I see no plastic parts in the extension locks.

The design of the center hinge lock is even better because one does not have to smack it after releasing. One simply squeezes the knob toward the ladder rail until retained, then open or close the ladder until the lock pins spring home at the next lock angle (folded, step, or extension). The only plastic parts in the center hinge area are spacers riveted between aluminum plates.

One of the compromises chosen to keep the weight low, and the storage size small, is lower rung tread depth. The treads are about 1-3/8 inches deep with hard edges. Standing on these in running shoes gets old faster than standing on my big 36 foot type 1A Werner which has rungs about 1-3/4 inches deep with rounded edges (but weighs 80 pounds). In the lower configurations, the 12017 has more rungs that are doubled by the overlap. The two rungs together give a tread depth of about 3-1/2 inches. One can stand on these all day.

I peeled most of the vinyl stickers off, then waxed the rails with car wax. This allows easier adjusting, and reduces the risk of pinching one's fingers by lowering "stiction".

If you're still reading, you're probably looking at the Werner MT-17 too. At the time of purchase, I cared about these 12017 advantages:
1. Rung tread depth is about 1/4 inch more. This doesn't sound like much but one can feel it.
2. Weight is about 6.2 pounds less. (I weighed both with a force gauge accurate to 0.1 pound.) It's obvious when one picks them up.
3. The extension locks make using the ladder easier.

In summary, the 12017 is a good choice if one wants compact storage and low weight in a good design that is well built. It's a 31.4 pound type 1A that goes from 4 to 14 rungs. It's just light enough that I'll grab it for step ladder use.

I do not give five star ratings very often. To me, a five star rating means there is little or nothing you can do to make the product better for the price. This ladder not only deserves a five star rating but also deserves what is becoming my new rating of "Just Buy It." If you own a home this ladder is a must have.

My only complaint about this ladder is that it is heavy. I knew that when I ordered it. It is heavier than my step and extension ladders that it replaces. However, it is rated for 100 pounds more than my other ladders which is good because I weigh a bit more than their 200 pound "limit." I find this ladder so useful around my house that I am even considering buying the smaller version which is about 10 pounds lighter just for indoors.

I originally imagined writing a review alerting viewers that this is not a replacement for a standard step ladder because the Little Giant has the thin rails of an extension ladder which are hard to stand on for any length of time. I was prompted to write this review today because I noticed that, when in the step ladder configuration, the two thin rails line up making a very comfortable step. Even better, at the top of the ladder there are four rails lining up making a much stabler platform than you have with a step ladder. This is an excellent product. Thank you Little Giant for re-inventing the ladder.

Update: The Little Giant could have saved the healthcare system $100,000. How you might ask? Well, I was trimming the dead wood from my Maple trees last Summer and the Little Giant that I purchased did not quite reach high enough so I pulled out my old extension ladder. I have to agree with my brothers that a traditional extension ladder is easier to "extend" in place than the Little Giant--you just pull on a rope. You have to lift the weight of the Little Giant extension to extend it into position (It would be pretty easy to add this functionality to the Little Giant, yourself). My house and trees are on a slope. My extension ladder has a straight base, not very stable on a slope. The Little Giant has a flared base and top for hugging the tree, much more stable on a slope (plus they have a extension you can add to one leg to level the ladder out). Well, I did not think to bring straps with me to fasten the ladder to the tree stem and the ladder slipped off the tree as I was descending. Five days in the hospital and two operations later, I now have a hundred thousand dollar wrist. If I had purchased the taller Little Giant then the accident probably would not have happened.

I bought this ladder with one project in mind, but it has already made two others much safer and easier to perform as well. The first, we hung a 65" TV on an open stairway wall that was totally unreachable before. The bottom of the stairs turns through a door with a wall about three feet from the bottom stair, placing the foot of the ladder against this wall then scoping the ladder out and extending both sides to the last adjustments was just long enough for the top of the ladder to be spotted one step down from the top to prevent slipping. I was able to easily mount the TV bracket to the wall standing on the horizontal rungs. When it came time to mount the TV to the bracket it was too damn big to do by myself, so with a friends help we carried it out to position, a bit scary trusting a ladder with approx. 450 lbs. probably more than the recommended max weight, but what are you going to do? However the ladder didn't even squeak we hung the TV and all is well. The 2nd job outside the house is very uneven terrain with no landscaping done yet a normal ladder rocks and tilts when accessing the roof. This ladder has the neat little kick stands that stabilize it making it much safer. The 3rd is the height and stability it has in the step ladder mode, our shop has 11' drop ceiling and doing electrical and plumbing work up there in the past was sketchy at best having to stand on the top rung of a normal 8' step ladder, not the best practice, but again what are you going to do? This ladder when extended out nearly scrapes the ceiling and with the extra wide base it is very stable when working at heights.
I have seen some comments complaining about the weight, but to me that seems a bit ridiculous. If you don't need the height, strength, or stability this ladder offers then use a regular ladder. They all have their uses this is not the ladder for a quick grab something off the top shelf and put it away kind of deal, it's for those tough scary jobs that a regular ladder just can't perform. Don't get me wrong it is heavy, it was like wrestling a dead bear to get it into that tight stairwell and then set up, but once it is set up, there is nothing safer, stronger and more secure.
All in all a great buy 5 stars for sure.

Update 10/23/19 nearly three years later and I still love this ladder!

I have the 22 model.

As this ladder is expensive, I read many of the reviews before buying. It seemed some of the negative reviews were written by people that had not read the manual. I read it before buying. So I already new that you do not pull the two ladders section apart, and than use them as two step ladders. If you pull the two sections apart you have a pair of trellises to hold a long platform, not two ladders. I wish it were not true, but it is in the manual, so why complain that the two ladders are not stable or that they break when used apart? Others reviews have difficulty opening the ladder to full extension height. You are not supposed to do this with the ladder standing up, but down on the ground. Then you lift it as you would any large ladder (push one end against the wall and walk it up). It is a legitimate gripe that you cannot extend a section while the ladder is vertical (like a typical sectioned extension ladder with a rope and pulley). It is one reason I do not give it five stars, but it deserves more than one or two star? Also, of course it is a little heavy for a step ladder - the height and weights are listed right on the product page. As most of the negative reviews seem to be for "documented features", I bought it based on the good reviews. But it is true, it is heavy and not as versatile as one might hope.

I'm Glad I bought it. I was very pleased with the ladder when it arrived.

I also found that I did not suffer from the complaints of other negative reviewers. Some reviewers had serious issues with plastic parts, and shipping damage. Neither proved true for the product shipped to me. It arrived in days. The trellis braces (parts you put into the outer ladder parts when you pull it apart to make two trellises) that I received were not plastic (like some received), but very solid metal. The moving parts work smoothly, and I have the feeling things are secure - the quality feel gives me confidence compared to the Werner. (I had tried a similar Werner, and it was not as solid.) There was no shipping damage, but one reason for less then five stars is that it was shipped in a simply thin cardboard box that was ripped in two places. I think some would need to return a ladder due to shipping damage.

Using this ladder in a "stair" well is the is the best. It is what drew my attention, and it works great.

Again it is heavy, I knew that it would be heavy, but it is a negative point.(It pulled the ladder hanger off may wall.) My fault, but still something to consider is that a single purpose ladder is easy to carry and store, so read the specs.

Really solid ladder.