Hi, Patrick,
I know the 430 pretty well, and it really is a pleasure to drive. The funny thing is, though, the FF is so good all around - handling, ride, engine, tranni, interior ergos - that I wouldn't say the 430 is more fun to drive, just different. The 430 is the kid brother you do crazy things with; the FF is the cool older brother that is good at everything.
Oh, but the 16M...now that's a whole 'nother story, brother!
I'm not sure if I should admit this, but I'm not a fan of the California, at least on the track (don't have much road time with it)
I respect and like the 599 GTB (no experience with the 599GTO) and got to know if fairly well on very nice Swiss roads, including some INCREDIBLE Alpine passes -
But the FF is "superior" in almost every way (except looks)...(sorry to the 599 owners out there, just my personal opinion)
Bugatti Veyron - Don't let me forget to mention, it's fast...
;-)