One week ago this beast replaced my previous DD.
This is one of the first cars I have that I have mixed feelings about.
It is very fast in a straight line and the torque is amazing a real counterpoint to the previous M3, but the sound is going to take some getting used to, sounds like the engine is under a pillow until you get it above 4500rpm. That was one of the most pleasurable aspects of the M3 was the engine sounded terrific.
The M5 feels like a plutocrat mobile, it rides well, is very quiet and solid feeling.
The handling is amazing in that you cannot believe that something that weighs 4200lbs will corner like it does. It hides its mass pretty well but it is still there.
I debated for quite a while between this car and the E63AMG S. That car has a truly MONSTROUS engine, but 4wd not as much fun and the transmission isn't as good as the BMW DCT which is really nice.
So far I am liking the car(has great seats which is nice for someone with a reconstructed lower back), but I have a feeling that I will trade it in for a new Z06 when it becomes available.