Using this on recommended commercial carpet without padding but it's not thick enough to maintain a level rolling surface. Probably OK for super-thin carpet.
I'm using the chair mats in my sewing room which has berber carpet. I'm hoping these will hold up better than ones I've purchased in the past. The old ones cracked and chunks broke out of them after just a few months of use. These are really smooth and easy to clean and chairs roll really nice on them.