I have been considering buying one since I keep getting tendonitis in my cutting arm. Saw a demonstration on the GO! last Friday and quite honestly, I think I could cut through 6 layers of fabric easier than turning the crank. I do One Block Wonder quilts so I have a need to cut 6 layers at the same time.
Quite frankly, the only one I would consider is the new electric one and that one just costs a fortune.