I own several of each, rotary, PC and Cyclo. I also own an old GEM orbital that is now used as a boat anchor
If you wish to know where a Cyclo stands with the PC, my hat would tip towards the Cyclo for power and aggressiveness. The PC will bog down if pressure is applied while the Cyclo will keep going. I use my PC mainly for final polish/wax application and I choose to use the Cyclo after the PC if the PC doesn't give me the finish I want before I break out one of my rotaries.
The Cyclo loses a few points in the hard to reach areas because it has a larger surface area and the PC has a better pad assortment to choose from than the Cyclo. The cost of the Cyclo is almost $150 more than the PC but the Cyclo is also built like a tank. One of mine fell off a wall about 3 1/2 feet high and nothing broke and still works great.
I am making my own pads for the Cyclo so I personally have a greater pad choice now than one does for the PC.
As for a rotary, tread with caution:scared You have the right idea by practicing on a spare hood or door. Right now just start off with "wet buffing", which means to buff the product until it just starts to dry or haze. A typical set up would be a polishing or finishing pad and a product like Meguiars #9, #3, Menzerna Final Polish, or Vamilla Moose, set the rpms at about 1000 - 1200 and use just enough product to cover an small area, usually 2x2. Buff the product into that area, pad flat as much as possible, with just a few steady passes and stop. Wipe off the excess and continue on.
"Dry buffing" would be buffing until all the product is gone and there is hradly anything left to wipe off. This allows the product and machine to work better but also has the risk of paint burn through if not experienced.
Use your hand as a guide. If you touch an area just buffed and it is cold to the touch then you can afford to be a bit more aggressive. If the paint is hot, then you need to back up on the pressure, speed and/or staying in one area far too long. The paint should be nice and warm to the touch, more on the warm side than the cool.
Swirls are the result of wrong pad/product selection, contaminated or chewed up pad, and/or fast, jerky movements.
Always using the least abrasive product/pad choice first and using smooth steady movements will greatly reduce the swirls.
Lastly, I always recommend people, when practicing on junk car panels, to BURN the paint! Thsi way you will get an idea of what a buffer burn looks like, smells like and just what it takes to get a "burn through".
Well I apologize for the ranting....hope that helps,
Anthony
The "spare hood" idea is smart, you don't want to try "on the job learning" with THAT particular tool.