BMW does a great job with their suspension. Road feel is superb. Goes around corners fast and flat. Classic styling still looks great. Has all the nice features you expect in a car of this class. The 4.0 V-8 has a lot of power, but can cruise on city streets at 35 mph or on the freeway at 65 mph (if you can restrain yourself). When I drive my 540i, I feel like I'm treating myself to a nice car. The V-8 does drink premium, so be careful with your right foot. Also, make sure you have plenty of $$ for all the maintenance and repairs these cars need. I feel it's worth the extra money to be able to drive such a fine sport sedan.
Handling, steering and performance are world class. The interior is very nice - you can feel the German influence, but it has a nice luxury feel also. I upgraded the stereo and it's fantastic! Car looks great - looks fast while sitting still.
The transmission has a major issue with the valve body. Also, the nikasil block problem gives BMW a big black eye. I've had to replace quite a few parts and the normal maintenance is very expensive - either pay now or pay more later!