In my opinion, it's all about the prep (like most everything else).
I spent 13 hours last weekend on the paint of my daily driver (1998 Acura CL 3.0), 11 of those with an orbital. In the end, I just used some Griots wax, but the car looks unbelievable. And this is with a White car. I couldn't imagine the pain and suffering of owning a black car.
I am looking into buying the entire Griot's polishing system and buffer. My car is white also, and I want it to look new again. Did you use their entire set-up, or just the Griot's wax?