There is no definitive answer.. paints vary from model to model, manufacturer to manufacturer. They will react differently. I can get swirl free on my acura Cl-S with light cut foam and 205.. that same combo wouldnt touch swirls on many cars out there. If you're going to correct paint for a living, you need to have a combination of many different pads an polishes in your arsenal.
Not only that, hard paints might be some kind of cerami-clear.. and if so I've read on here that the top layer of the clear is the hardest.. and aggressive polishing can remove or damage this layer making your "hard" paint.. soft! or weak.
D300 And Megs MF are pretty awesome as a cookie cutter approach to detailing.. but throw in some single stage oxidized white toyota paint and from my experience foam will out perform the MF's hands down.
Surbuff MF's cut like hell.. last week I had a severely neglected black come in for a 2 step polish. The megs MF cut better than the Surbuffs and finished better.
Yesterday I did a 2 step on a 1990 Vette single stage black, Megs MF and D300 did nothing.. Surbuff with D300 Cut everything quickly and set me up for my second step > Med Foam + D151.
