Heh heh,yeah, this post is sorta down my alley. I do about 90-some % of my correction with 3M's PI-III products. General comments on the PerfectIt stuff I've used follows:
The PI-III EC 05936 is pretty aggressive stuff. I only use it when I really have to (which is hardly ever these days, unless I buy something that's really trashed) and it doesn't finish out as nicely as I'd like. Still, it *will* do some serious correction. Not for the novice though (IMO). *I* woudn't go straight from this to SMR but that doesn't mean I'm saying that there's anything wrong with doing that if it works for you. I use PI-III RC 05933 or PI-II FCRC after this as I prefer a more gradual step-down and these compounds take out the micromarring faster than doing more work with milder stuff (yep, an extra step that saves me time overall, and leaves less chance of hologramming).
I don't use their SMR at all as I don't want any fillers/concealing when I'm working with a rotary; if I have issues I want to see them. Again, that's just me. I will say that I couldn't get a finish I'd be happy with using only the Extra Cut and the SMR but again, that's just me. FWIW I can't get a finish I'm satisfied with without using something like 05937 after *any* of the 3M compounds, even the milder ones discussed below.
The PI-III RC 05933 isn't nearly as aggressive as the Extra Cut but will still do correction. It finishes out almost ready-to-wax. Unlike the 05936 this can be used by hand/PC/Cyclo, though it's pretty mild that way. It's a good product for people who want something slightly aggressive and IMO the name "rubbing compound" is kinda misleading. I follow it with the PI-III MG 05937 which will leave things good enough for all but the most particular (I use even finer products on the "good" cars and yeah I can tell).
The PI-II Fine Cut RC (39002 in the 16 oz. bottle, forget what the quart size's number is) is very similar to the PI-III RC 05933. Just a bit more aggressive, doesn't finish out quite as nicely, probably because of the "old school" silica-based abrasives (which you don't want to inhale). Like the 05933, I follow with 05937 to get a ready-to-wax finish.
I hesitate to say the the milder RCs will substitute for the Extra Cut as I find the 05936 *very* aggressive and I find those milder products *very* mild. I will say that while the 05936 can save time with major correction, anything *I* feel safe removing will come out with the 05933 and a bit more time. But note that I'm a fanatic about maintaining thick paint and I'd rather leave flaws in than thin the paint too much. And I don't have to work on severely marred cars any more.
No experience with the 3M pads, none with wool pads on a rotary at all. Just a matter of my situation- any car that needs stuff like Extra Cut/wool is beyond the condition I'm interested in. Ah the luxury of only doing my own cars
