I got a small rotating mat a few years ago, back when they first became available. I didn't care much for it because it seemed to have a high center, and when I cut, the edges of the mat moved down to the table and my cuts were off. I stuck it in a box somewhere.
One of my cutting mats is a 12" square, when I need to rotate it, I just put it on a piece of plywood that is about 18" square, make my cut, then rotate the plywood.