I purchased a Black/Black 750iL in June of 2006. I've never had to go back to the dealership for any service other than a nail in one of the tires. I've owned Lexus, Mercedes, Nissan, Toyota, etc., and this as been the most trouble free auto yet. I really enjoy driving the car and have become spoiled by the many automatic features (door close, keyless start, bluetooth, etc.).
Comfort and space. My friends argue about who gets to sit in the back seat! This car really moves and is nice and quiet on the road. Other features: heated/cooled seats and, although I never thought I'd use it, the heated steering wheel. You can adjust the seats to almost any position.
Reading MP3 CDs could be faster (initial load can take some time), Real Time Traffic integrated with the Nav, aux port for MP3 player.