I guess when you order cheap you get cheap. My chair still does not roll on this mat. It is actually worst than the carpet was. I need to return for a thicker mat. Not worth the money.
As far as the mat functionality it's fine. But it has a tacky surface and no matter what I try I can't get rid of it. It's not from the tape that it was rolled up in it's the entire surface that's tacky. I wear socks when I use it then take the socks off when I walk around the rest of the room so it won't make my floors sticky.