I have had issues with cheaper mats and my chair wheels digging pits into them specifically bought this to avoid that and I'm ready to throw it in the trash after using from New Years to mid-April. It gets a lot of use but I weigh 185lbs would think that it could handle an average-ish weight but nope.
I have only been using it for 4 days and I already have ruts where my chair rollers sit. It is a real nuisance to roll around and I don't even have a very thick carpet! This is rated for medium pile carpet and it was supposed to have a lip which it does not which is fine with me. I wonder however if I received the correct mat. Regardless I plan on returning it as soon as I can. Also it was received with curled edges - I had to use a hair dryer to get them to flatten out. I'm not a happy camper as I don't have time for this!
Good chair mat works with worn carpet my carpet is almost to the bare floor and it sticks very well. I wish it could be a little larger by 2 inches all around but OK so far.