This mat looks fine grippers on the bottom work well size is fine. BUT it’s very soft plastic so your chair wheels press into it and make it very difficult to roll or move around. It’s not at all like rolling on a hard surface floor. This is on very low berber-like carpet. Disappointed.
It is expensive. The cleats aren't nearly big enough for the thickness of carpet this is supposed to work for (3/8") so it slides around. It works otherwise with no cracking yet. It flexes a lot too so you need to rotate the wheels periodically so you don't create divots in the mat. Not sure it's worth the premium given it won't stay put and still flexes a lot.
I purposely waited over a year to review this product in order to determine how it stood up to daily use. Some plastics will break down and crack. I'm happy to say this product shows no signs of wear and tear yet. No cracking.
The mat's knobbies on the bottom are just right but it didn't flatten out all the way yet. I have had it a week. Took 2 days just to get the thing to unroll and then I had to point a heater at it. Maybe this summer it will finish flattening....