I wouldn't bother - go for a 370 instead
They're certainly no nicer inside than the 370 (the newer sDrive ones are by a big margin, but then you lose the driving experience) and the reliability just doesn't cut it. On top of servicing and other repair/parts costs (around double Nissan's rates, I'd have thought), you've got to factor in a replacement of the Vanos units every 3 years ish (it took Williams Liverpool 2 weeks with my car, so that won't be cheap - mine was JUST under warranty) and replacing the rear springs every 1 or 2 years as they snap at their base. The springs themselves were £100 I seem to remember, plus time or cost for fitting them. Nowhere near the same levels of kit, either.
Thanks for the info, always good to hear from some one whe has been there.