Haven't had it very long. I am over 200lbs so I sink a little. I've rotated it occasionally. Hasn't slipped so the sinking was sort of expected for the price. It actually does help keep the chair in place ... and I easily "pop" out to roll. The spikes aren't anywhere near as deadly LOL as they were in the past. I'd give it 5 stars for the cost and quality if I didn't sink... but I think I probably would with a $100 one anyway.
I recently purchased a 36"x48" low-pile carpet mat for my office chair. Despite all the supply-chain shortages Staples had the one I use "in stock" and delivered it with two cases of copy paper. Everything arrived in a couple of days and in excellent condition. I applaud Staples for keeping their stock of products available for purchase.