Absolutely top quality ride - there is no substitute. 50/50 weight distribution and the understeer issue that existed with the e39 M5 has been drastically improved. Exterior still maintains the stealth look, but upon closer inspection has a more muscular stance than other 5-series and of course, the tell tale oval side mirror housings and the quad- tail pipes. Great color options (but still no BMW individuals colors for the US). Interior has improved over the previous model with more comfortable seats - you can sleep in these babies and full leather package with alcantara headliner is gorgeous. SMG is great, but takes a bit of finesse to get smooth shifting in paddle mode.
Power, stealth, and comfort. This car will never leave my garage (well, at least until another new M5 comes out). The V10 engine has won many awards and it is easy to understand why - 8250 RPM limit - this baby is in it's sweet spot between 5500 - 8250 RPM where it just takes off in every gear.
iDrive - don't really care for it. iPod integration (supposedly July 2006). Automatic mode in lower settings/rpm lags too much between shifts. Would like to see European launch control in US model. These are minor items - it is very hard to keep this car under the speed limit!!