I've used 1, 3, and 4. They get the job done. The Griot's system has one polishing pad and you adjust the cut by the polish although they will be fine with any pad. The whole system is designed to be safe for weekend warriors.
Polishes 1 and 3 are like 105/205. Polish 4 makes for a good paint cleaner. I wish they were easier to remove. I think I'll keep them in my arsenal because I can get it locally, but I'm looking to try some other polishes.