The M3, at 3700 lbs, is already past my personal desired weight for a sedan. It's my main beef with the car. Adding 500lbs more weight on top of that, and gobs more power to mask it, will *not* make for a better driving experience.
If you think the new M5 is the dog's balls, then by all means go buy one. I think its impressive, but only to look at from a distance. Sort of like the first time you see an elephant urinating. Big stream, but ultimately still an elephant.
2015 F80 ED
2004 Z4 3.0
2014 X3 35i