Over all chair will roll over mat better then on carpet. My big issue is when it was shipped they rolled it up and used clear packing tape. It took 3 days to get the mat to lay flat and I'm still after 4 months trying to get tape residue off.
The large area of this mat provides complete protection of the carpeting around the seating area of my desk. This is the second one I have purchased. The first performed well for 15 years before cracking in the most used area.
We looked around quite a bit for a rectangular chair mat for office carpet in this size and of all the places we looked this was the better price and was delivered the next morning for free! Very happy with the quality.