I do not know why I ever left BMW. Maybe is was that the grass looked greener at MB. A Benz is probably the best car to ride in, but the BMW is the best car to drive. And I like to drive. I am coming out of an 07 E350 and just bought a 08 528i. What a difference. The 528 is so fun to drive, that I cannot wipe the smile off of my face. It just handles so well and there is plenty of power in the 528. You really do not need the 535. It definitely reminds me of my 2000 528 which I liked very much. Purchased car with premium & sport packages, navigation, auto, iPod and xenons. Great package. The E350 was like driving a sofa down the freeway. The 528 is like a sports car, it is on rails.
Handling, styling, new auto shifter, iDrive (and yes iDrive is complicated. If you want a information center to provide a lot of features, then there will be some amount of complication, but it blew me away) and the comfort seats (none better).