paul woolson
I've got wall-to-wall horse stall mats in my shop. I'd do it again in a New York minute. In fact, when I built a small addition, I had the floor down before it was completed.
I see absolutely NO negative to them. Machines roll just fine. I've got a 900 lb wide belt sander that isn't leaving any dents at all.
They are a complete pain in the neck to install because they are so darn heavy and hard to manipulate. But if you get a buddy (might have to be a pretty good buddy) to help you it should be fine. I did mine alone but likely wouldn't be comfortable doing that again.
The very best part is when you drop a chisel on them you don't have to take it back to the stones.