Seriously?
It may work for one thing, but it's pricey for that, and ab work with a stability ball is more effective overall, IMO. Also, you can do a lot more with a stability ball.
Try that, in conjunction with reducing body fat (as many of us have good abs, just under a layer--or two or three!--of fat).
My neighbor, for whom I cat-sat once, has one, and she doesn't show any signs of having good abs.