Spin classes were good for me, but mostly for the workout. The workout is what you make it, but I always found it easier than cycling. Ain't got no 50-lbs freewheel on my bike...

I went 1-3 times a week for a few years, off and on. When they still use the same songs/music in '06 that they used in '04, one tends to burn out.

Now I'm no longer taking spin classes, but I'm riding a lot more than before.




EDIT: I agree that you have to hydrate more, and the warmup is not all that grat (usually one 3-minute song), but it's geared more toward fitness than cycling. TO each his own I guess.