OK, I am actually working on a video using SIP and 106FF via PC so here is my take on the whole pc/rotary thing.
While shooting the PC video I decided to shoot a section showing the difference between the PC and Rotary.
Here is the before shot:
Below is after (with one pass of each product) SIP LC orange pad & 106FF LC White pad.
Rotary
SIP - pyramid up to 1500rpm
106ff - pyramid up to 1500rpm
PC
SIP - 6
106ff - 5
Here is a side by side -
Left Rotary Right PC (this is after a wipe down with alcohol/water
Here is crops of each side:
Cutting - with one pass of each product the rotary was faster and eliminated more RIDS then the PC - of course.
Finishing - The advantage is to the Rotary again....but only slightly, the PC left the finish just as glossy as the rotary but because of the presence of more RIDS the clarity was better with the rotary.
Here is a video of the two sides:
Rotary & Porter Cable Side by Side
Now this was on black, but I also did this same thing on metallic blue/gray paint and saw no difference between finishes of the two sides:
My conclusion is a PC
can breakdown polishes and
does leave a great finish....with proper technique. Is it better than a rotary, no not at all...but with proper techniques this is all an enthusiast will need for normal wear and tear on the paint.