I have the 12x12 square one; got it at Michaels with 50%coupon; it's also sold at Joann's.
It's annoying, it does not turn easily and on my cramped/cluttered cutting table it's always bumping into something.
I have an enormous stationary cutting board (about 36"x24") that I've had for 20+ years and use for strips.
The rotating cutting board that I found and love is an 8" round one...The pieces I cut are rarely larger than 3"x6" which fit.
It turns easily and smoothly. It can be had from Come Quilt with Me, a mailorder vendor in Brooklyn, NYC. Pat Yamin, the owner, also sells very good templates which can be used for hand or machine piecing. Google the name and you'll get to her on-line catalogue.