Well I just got the Optimum MF cutting pad and wanted to give it a whirl last night. I'm pretty impressed. My experience is limited to Menzerna SIP with an orange LC flat pad, and I wasn't totally happy with it's ability to remove swirls. It does a nice enough job on my Pontiac's paint, but being black it shows everything, and it still left behind a minor amount of light random lines that resembled spider webbing.
It was late in the day, so I didn't have the best light, though it was still sunny enough to get a pretty good look. I really wanted to put this thing to the test, so I took one for the team and lightly swirled around the paint with a stiff bristle carpet brush (it's a 9 year old car that is starting to rust, so don't cringe too much). With the poor light (and my work light has burned out bulbs) I had a heck of a time getting any decent pictures, but here is one of what I started with.
I taped off in the middle, and did a pass (3 up, 3 down) on the left with the mf pad and SIP using my GG polisher, and on the right with the orange pad and SIP. This is a crappy picture (with a couple prior scratches left), but you can see the tape line untouched in the middle. Both sides came out nice, but it appeared that the mf side came out with just about zero swirls.
I'll have to use it more to be sure, but I think there might have been a couple other added bonuses I seemed to notice. For one, I think the mf seemed to dust less than the foam. The other was that the polish seemed to work quicker with the mf side. With the foam, it seems to require at least six passes per section, where I think with the mf I could have quit after four. But I'll need more than 15 minutes with the pad to really get a feel for it.