I note that Tractor Supply now has their Thick Rubber Stall Mat on sale for about thirty five bucks. I’ve had one of these big boys between my bench and set up table for several years now and, I promise you, any other mat you’ve ever seen is insubstantial by comparison.
This thing is 4’ x 6’ by ¾”, seems to be made out of the same rubber as truck tires, and weighs about as much as a year old heifer. You couldn’t hurt it with a backhoe. If you should drop a chisel on it the mat will just shrug it off, and it will certainly save you some grinding.
If you decide to get one I would suggest leaving it out in the sun for a few days before bringing it into your shop. Mine initially smelled like something that had crawled up out of the La Brea Tar Pits but after a good airing out has no lingering odor. Anyhow, it’s a lot of foot relief for the money and you'll never wear one out.