I wonder if it's really that much different from an inexpensive ab wheel.
I have an ab dolly (sis bought one, and it was a BOGO deal, so she gave me the free one). I don't think it's really much different from the standard ab wheel as far as the actual muscles worked. Because of the full rotation on the wheels, it allows for some different movement.
and the dogs find it very entertaining
I'd love to know what they think when they are watching me exercise...