I think you'll find it's a wonderful tool, Ken. Useful for when you can't use the feet so easily, or when a ride outside isn't happening, or just when you want to shake things up a bit.

Definitely poke around, on the 'net, regarding possible ways to take your cardio out for a spin. (Definitely toy with the combinations of resistance+speed, as it's appalling how different they can be, particularly over a good amount of time or over an intervals course.) Can be a great workout, one that I find to be rivaled only by swimming, (trail) running and cross-country skiing.