I bought the four foot model and installed it the moment it arrived. I use this at my front entrance door and it works great. The electric wheelchair I bought has no trouble going up this ramp even at the lowest speed setting. It folds easily and although I don't use it that way (I leave it down all the time) it is a great feature.The edges also have a lip that sticks up to prevent the chair from falling over or off the ramp.
On the negative side that can also be bothersome if you have a storm door as they don't allow the door to close. On the plus side they do keep the chair from running off and possibly causing a fall which is most important. I'm working on a solution to that problem.
The ramp is both strong and sturdy with no flex that I can see.The non skid surface life is yet to be determined but that would depend on climate and how much heat/cold it is subjected to as well as the amount of traffic is has to bear. Time will tell but it allows you to take it with you if need be although it is a bit on the heavy side but if you are in moderately good shape you can fold it and lift it and the handle proved is fine for that.
Highly recommended product.

I've had this ramp for 4 years now so I can talk a little about long term use. These ramps are incredibly sturdy. I've used mine everyday, multiple times a day and they don't seem to have any problems with squeaking or looseness. They also can support quite a bit of weight, about 500 lbs (myself plus my big electric wheelchair)

Another reviewer said that the hinges in the middle stick out. This is true, I can confirm this. However, none of my ambulatory relatives have tripped on the raised hinges. Most do not have any mobility problems but I can say that my great-aunt who uses a walker did not have any problems going up and down the ramp. I think most people would end up walking on the non-slip portion of the ramp. Your mileage may vary.

The only con I can think of is a pretty major one; the thing can be slippery. If you plan on using this indoors on tile or granite or other slick surfaces, I highly recommend purchasing a rug pad to increase the friction to prevent slipping. I bought the gorilla grip rug pad and it works almost perfectly though I would still recommend checking the ramp to make sure it's even. I slipped once going down the ramp (with the rug pad) but luckily my brother was there to catch me before I bashed my face into the scratchy surface. Of course, all this could be avoided if you screwed down the ramp in the designated holes but this would ruin the floor it goes on.

Overall, it's an incredibly useful and invaluable tool but I would still suggest you be careful using it.

We built a new shed but we did not account for the ramp that would be needed to get things like the mower in and out of the shed. We did not want to build a permanent ramp because it would have stuck out into our yard too far. So we started looking for portable ramps and found this ramp. The ramp was well packaged for shipping and had instructions for how to secure the ramp so it does not slip and came with all the needed hardware to do so. This ramp folds up very easy and has a handle for carrying the ramp. This ramp is very light and is very sturdy when walking up and down it.

So perfect for our use. We got the 5' length ramp for our one step that is difficult for my 90 year old Mom to get up and down from. It is not heavy and I can carry it by myself for use on the front porch if we need.

I bought via Warehouse Deals. Ramp is unsafe if being used to walk on/up/down. Couldn't tell if the welding patches near the seams were original or done by someone else who purchased before me and then returned as "new". The hinges on the ramp that allow it to fold up do not recess into the seam once the ramp is opened. The hinges stick up and become trip hazards. I bought the ramp for my elderly father who has trouble navigating steps. He would have tripped on those hinges if he tried to walk up the ramp. If these hinges were the original configuration or someone modified the ramp and then returned it, I can't tell. Regardless, the ramp as I saw it is unsafe--I returned it.