I'm an avid cyclist and still purchased a spin bike to be able to do those hovers and standing work I never used a trainer on my road bike but I would think the spin bike would be much more comfortable and "safer" with regards to doing those hovers that Cathe does (too many!! LOL).
Absolutely. I actually used the trainer for a while, and found all the standing work to be torture. Once I switched to a spin bike I could actually follow the workouts. I think if you want to use a trainer it would be better to get workouts specific to that.