I have a '99 540i and I'm thinking of getting into an M5. Are there significant differences in handling, torque, steering? Is it worth the $$. How about down time? how much time do the M's spend in the shop. What's the most common problem, and do driving habits make a difference. Any advice is welcome. New or used? Will I save big $$ on a good use one? What should I look for in a used that signals a lemon? ---- Thanks