I've only had this mat about a week so some things - like durability cannot yet be judged. So far 1) Folks complain these mats often come rolled up in a box and are difficult or impossible to get to lie flat. This one came on a Staples truck and was flat. It was left on the front patio where it did take on a bit of a bend because of where it was placed. However I laid it in the 95 degree sun for an hour and it was like a limp cloth. Put it inside on a cooler hard surface to let it cool off flat. Then under my chair. 2) Some have also complained these mats have an odor. This one had a slight odor immediately after bringing it in from being in the sun. However once it cooled it seems to have no odor. (Wife has a very sensitive sniffer and she's not said a word about an odor.) 3) The "cleats" on the back are doing an OK job of holding this mat in place but no better than the spikes on my previous mat. (Doing the paperclip test the carpet depth to the backing is 1/2". Of course pad under that also about 1/2" I think.) 4) The mat is soft enough that it dents from just the weight of my 4-wheel oak desk chair. However the dents do not seem severe enough that they prevent me from rolling around on it. Not as smooth as say smooth hardwood but a) better than on the carpet and b) better than on my old on which was falling apart. Bottom line seems a decent mat for the price. Gave it 4 stars because of the cleats not holding as advertised and because of the denting.
I am disappointed in that the mat is supposed to be for use on carpeting as I sit on my office chair its wheels make an indention into the plastic. I hope it does crack soon. (BTW I"m only 200 lbs )
As other have said this mat will move so that every 3 or 4 days you need to reposition it. Also you do get slight indentations from the wheels but it is not enough to keep you from rolling. For the price this mat is ok for the job.