Here are the main machines used to detail and the order in which they rank their ability to remove defects.

True Random Orbital (RO)
1.Store bough 9 or 10 inch buffer - useless
2.Porter Cable - mostly light duty polishes and upkeep
3.UDM - 20% more power than the PC althoughs feel like more.
4.Cyclo - More powerful than the UDM. Works well with medium and light duty polishes.

True Dual Action
5.FLEX 3401 VRG - combination rotary and RO - more powerful than any RO.

Pure rotary
6.Rotary - Dewalt, Hitachi, Metabo - Can use with heavy polishes, foam, or wool with 6-10 inch pads. These have the ability to correct the biggest defects but run the biggest risks for damaging paint.

 

I made the switch from the PC to the Flex, and the money spent is well worth it.

 

Not true at all--a PC will remove just as much if not more clearcoat than a rotary. Take a look at this thread:

http://www.autopia.org/forum/car-detailing...-shock-you.html

 

One of the key things about the rotary is to learn not to stay in one spot at all. Keep the pad moving at all times. Also, tape off or avoid edges and trim pieces as you can burn them fairly easily.

 

There are some caveats to those findings, as I read it:

1. They are talking about deep scratches and heavy paint correction.
2. They are talking "extremely skilled" rotary users - those that can polish accurately and do the final finishing with the rotary and not require any follow-up (holograms, etc).
3. Other serious issues are likely to present themselves with an inexperienced rotary/wetsanding user.

1 and 2 deal with paint thickness. 3 is just serious enough to be concerned about with a car that costs $30,000 and would require expensive paint work to correct an "oops"