I like to belive that both a Rotary and PC should be part of detailers arsenal.
Before you attack your car with a rotary get someone to show you how to use it, then practice on a junk piece. IF you go into a pannel show and offer one of the detailers or other technitions a slab (24cans) of beer or bottle or bourban, Im sure they'll give you an hour of their time.
If you have to pratice on you own car get a finishing pad and something mild like Meguiars #9 or #81 even a machine polish #3 and get the hang of it.
Always use the least abbrasive method first and step up each product. IE.
1. Cut or compound.
2. Swirl remove Light cut
3. Swirl remove polish.
Also my tip is to alway make you last abrasive sep one off a swirl remover with a PC. I like to use 3m Perfect it III Machine Glaze with a Meguairs Yellow polishing PAd. This will remover those swirls and buffer marks from the rotary that even a professonal may have left on Dark cars.
Good luck
Sorry for the long post