Flaws:
Big, Bulky, Heavy.
When you open it feels like sand paper - Not smooth at all even with lubricant. Can't open one handed even after 2 months break in period.
Replacement razors stick together and compartment hard to get open without fingernails.
Didn't come lubricated.
5 minutes after writing this review I swapped out the crap blades that it came with, with lennox gold blades but the auto loader jammed, got it un jammed, took out two blades thinking they were thicker but even with one it still wont load properly. Wont even let me open the tool. Now having to scratch up the slider more to un jam again. Sigh Docking another star.

Neutral:
Comes with some razors, not great quality but worth noting.

Happy with:
Auto load function, Also note you can manually flip the razors around to use both sides of the blade to not be wasteful.
Tight fitment
In order to fold, Blade must be fully retracted - prevents unnecessary slicing if you know what i mean. Also love that I can extend just as much as needed.
Carries well in belt line despite its size and weight, Feels great in hand and hasn't slipped out yet.
Has place to put pointer finger for precise control.
Auto loader uses magnets to pull new blade in place Just beware if around sensitive things.
Surprisingly the finish is holding up well despite being punished. Still as orange as the day I bought it. I also EDC it.

The quick release button does not function to release the blade. Amazon sent me a replacement, and that had the same issue as well, leading me to conclude that the issue is a manufacturing defect of this particular utility knife from Klein. If that's true Klein should recall this product, or Amazon should discontinue selling it until they do.

I had purchased a package of Stanley knife blades to use in my old utility knife. When I opened the package, oil was dripping from the blades and got all over my clothes. While I realize that it's necessary to have oil on blades, the Stanley blades had so much excess oil that I ended up throwing them in the trash, along with my old knife.

I checked the reviews on Amazon and decided to give the Klein Tools utility knife a try. Far superior to my old knife, this one is ergonomically designed, and very easy on your hands. You can use it for long periods of time, without any discomfort. The cutting quality is first rate, and the rubber handle grips make it feel nice in your hands. The internal blade storage area holds 6 additional blades.

The bottom line is that this is the best utility knife that I've used to date. It's very high quality, feels good in your hands, and does a great job of cutting without having to use a lot of force.

Did a lot of research before choosing this Klein Tools 44133 knife as I remodel homes and wanted a quality unit. Returned it today after 2 weeks of use. Worked fine at first (I'm not a constant user of utility knives) but then it started refusing to retract the blade. Discovered the reason was that the blade was coming slightly unseated. But then it got worse in that the blade wouldn't stay in while working, even doing something as simple as scoring sheetrock. The blade would come out so far that the locking half-circles were showing. Note that I was only on the second or third blade that came with the knife. Not a quality tool at all. As other reviewers noted, apparently something has changed in how it is being manufactured compared to the past.

Right out of the gate ... It seems as though I either got a bad one , or there are some flaws here . The small switch that locks it closed is both unnecessary and tends to push itself into the locked position when you insert it into your pocket . The cam on the spring assist is set to high and makes opening with one hand difficult . Wet hands , NO WAY . That trapezoid shaped button that releases the blade , it engages with little more than a soft breeze . So start growing out your fingernails , because you will be spending a lot of time bending over and picking up that blade . Most of the time it happens when the knife is closed , so this makes it even harder to open because the point of the blade jams into the plastic spacer between the scales . It does work about 75% better in your left hand because the one sided rubber thing gives your fingers a grip and the clip on the other side allows you to slide your thumb up while you open it . If it weren't for that , it would have been one star . Oh , the liner lock is nice .