I've used this mat for about two weeks now. I have a low pile carpet but decided to step up to the medium based on my time at my desk. Well worth the upgrade but my chair has slid into a "default position" that is slightly left of where I actually want to sit from depressions in the mat. But it's cheap plastic and I can't complain Delivery experience was weird. I ordered the mat at 430pm and at 930am the next day I got a knock on my door and a ring of the doorbell. I sit close to my front door so I was able to see the delivery guy jump over my garden and sprint across my lawn back to his white panel van after throwing the unpackaged mat on my front porch. I shouted a thank you and he replied. Nice guy. Mat wasn't damaged at all in that interaction but it did have a hefty layer of dirt grime and footprints that I had to wipe off inside with some towels on my hands and knees since my hose is off for the winter. Since it wasn't packaged I didn't have to wait for it to uncurl.
I bought the least expensive chair mat knowing we intended to switch from carpet to a hardwood floor in my office so I knew I would need to replace this mat at some point down the line. I like the mat that I purchased but the only minor complaint is that sometimes it shows indentations from the wheels on my chair on the mat. Other than that I'm very happy with the mat.
I don't think it is going to last very long. It is too flexible to withstand the weight of a 195 pound person without the chair casters leaving a deep impression. It will eventually crack and splinter and chunks will pop out and it will then have to be replaced again...just like the last one.