Let's also not forget the differance in Sat Radio units pre 3/08 and post 3/08. I have been waiting for an answer as to how to get "best of XM" in my 02/08 build M3 for 6 months now. Still no answer on that one.
If you do this to your leased car you better get approval, in writing, from your dealership. When I asked my dealer about doing this about 4 months ago when they started showing up, they basically just chuckled and said that they could do it, but by the time Labor is factored into the price it would be cheaper to trade in my car for an 09.
Having used both systems (girlfriend has an 09 335xi), I can attest to the CiC system being a little better, but not nearly worth the expense of ripping out the CCC system to put in a CiC setup. Yes, the screen has noticeably higher resolution, but it is used for a god damn map, not to play Call of Duty, so who cares (if you want to mod your idrive to play DVDs, have at it). The ability to scroll by letters has been improved, and the system feels faster when searching through my ipod, but again, not fast enough to warrant the swap. The shortcut keys are nice, but you already have shortcuts simply by holding the joystick in a particular direction. In fact, I find that to hit the shortcut keys I first look at their locations to make sure I am hitting the correct one (granted, this is still new. I imagine like everything else you get used to the button placement), but I doubt it will ever be as intuitive as simply moving the stick to the Right for Navi, down for Music, etc.
The UI is still slightly "off" in terms of menu navigation. It really comes down to me being annoyed that 6 months after I take delivery of my car, they decide to change the system. It wasn't like they didn't know the new system was coming out. They should have just rolled it out sooner, or charged less for the older system. Just my 2 cents.
12 E70 X5d Black Saphire/ Tobacco
08 E92 M3 SG/Fox Red Gintani Race, RG63
09 E90 335xi Crimson/Saddle 02 E46 M3 Cab Imola/Black (Sold-RIP
)97 E36 Z3 1.9 Atlanta Blue/Tan (Sold)