The role and necessity of dual action polishers

spearfish25

So I've long been a nut about waxing my cars. I've always done it by hand, but the work of it when I got married and added my wife's car to the mix became too much. I tried a $30 B&D buffer which removes wax a bit faster than hand, but I don't think it does much for quality. I'm now considering a Porter Cable, but I'm wondering what the real role of these polishers is.

From what I've read, the PC is more for polishing than waxing. Polishing seems to be a somewhat rare event...perhaps twice a year to remove swirls or to take care of scuffed areas in the clear coat/paint. I have some minor clearcoat scuffs that I want to fix, but I don't know if a PC is really necessary. Any thoughts on the added benefit of having a PC or other applications (for my Z) to make the purchase worthwhile?

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2013 Cadillac V-Wagon, RIP Z