I hate i-Drive for two reasons.
1. Put simply, it is terrible.  I have driven the 7 before, and I had great difficulty understanding/navigating the menus.  (For the record: I am under 30, I do computer programming, and not techophobic.)  Perhaps if I drive a 7 myself and drive it everyday, I will eventually memorize where to find everything.
2. The screen needs to sit under some form of a roof, which on the 5, 6, and 7 is another arch.  I just hate the idea of having 2 arches on the dash because it looks really dumb.
The 1-series seems to be an improvement in that regard.
I'm sure the new 3-/4- will not be exempt from i-Drive.  For this reason I decided to buy the E46 instead.