I voted. Thanks for the great giveaway. Autopia rules! Rupes 21 and Rupes 15, but my Rupes Mini would tie for third. I use all three on every detail. The Nano gets honorable mention. Rupes fanboy.
Although I use my Flex and Rupes 15, most often the curves, corners, and smaller panels I would tackle with the mini. Also for polishing after compounding, I find smaller pads to give results quicker. Mini gets the most mileage in this area. Next for compounding, I found my Flex to be king. Can be difficult to hold for long hours but the results speak for themselves.
Voted but you can leave me out the drawing. Only have 3 machines right now so kinda limits my answers. 3401 then PE8 then GG6.
Edit: Forgot I own a GG3, goes to show you how often that gets used. Works ok I guess but its quicker to change the GG6 (really GG5 as it always has 5" plate on it) down to 3" backing plate and use that as it works much quicker and better.