I've driven an M5 on a test drive before. The M5 is pretty amazing - you get tons of power but don't feel it, if that makes sense. 60mph on the highway doesn't feel much different than 90 or 100, and acceleration feels like it's done in an instant, you won't really know it happened unless you're looking at the speedometer.
The clutch... oh my god... beyond amazing. I don't know how else to describe it besides saying it's amazing... that thing must be a work of art, using it was a pleasure, easiest clutch I've ever used.