Ab Circle Pro vs. Ab Coaster Pro

This is it! The battle of the "pro" ab machines! Forget about those crappy amateur abdominal exercisers. We're in the big leagues now and we want to know: which is better, the Ab Circle Pro or the Ab Coaster Pro? These popular new "as seen on TV" ab gadgets are being marketed heavily and lots of people are buying them. But which one really works and gives you the best ab-building/fat-burning