Okay, I used 6 inch pads on my 5 inch Bosch Random Orbit Sander for years when I was either polishing or waxing my cars. I had not bought a dedicated buffer or my first Rotex at that point. Buffing or polishing with a ROS is slower than a Rotary Style buffer or Rotex in Rotary mode, but really safe for the most part.
For pad choices, at least from Festoo as I use them, it goes like this for the 6 inch/150mm pads:
Coarse Buffing, when faced with lots of defects or you want aggressive polishing to cut quickly, esp with a more aggresive polishing compound- Yellow Pad, part number 493845- Do NOT underestimate how fast this pad will cut, esp with a Rotary Machine.... [blink]
Orange Pad, the medium all-rounder, Part Number 493852. Depending on your buffing speed, pressure, and the compound you're using, this pad can deliver great results for a variety of surfaces. My first choice in many cases- [big grin]
Fine Honeycomb, Black -493887- For waxes or very fine polishing, very flexible, great with curves and uneven surfaces where you're transitioning from horizontal to vertical or similar usage. It IS more delicate than the Medium pad due to its construction and foam, so expect this pad to wear much faster if you're using it alot. Easier to get chunks ripped out of it as well.
White Honeycomb- 493873- I typically use Paint Sealant with this one or Paint Glaze at times. Not quite as soft as the black version, but again, much more flexible than the Orange Pad.
I rarely use my 2 Rotex's for waxing or polishing, as I own the 150mm Shinex. Unless I really need the small 80mm pads of my RO 90, the Shinex is so light and easy to control , that I grab it first for almost every application. VERY quiet too.
Hope this helps you out.... [cool]