Very happy with this. I read so many bad chair mat reviews with horror stories of them never flattening out, so when my partner unrolled his polycarbonate chair mat and it instantly went flat, I was worried to see this one that I bought for myself still kind of curved with little waves in it. I came in the next day with a heat gun ready to sort it out, but thankfully it had gone flat overnight. Chair moves smoothly over it, and the edges don't catch. Nubs on bottom are SHARP though, so watch out!