Engine Performance (was the primary reason for my decision to buy & quite simply the M340i is a car built around this special engine)
Gearbox (never disappoints. This version is F-A-S-T, noticeably faster than the ZF8 on my F30 328i)
Exclusivity
Exterior looks (Handsome car, love the exteriors & interiors)
Handling (M Performance Suspension, M LSD etc.)
Pricing (Surprisingly well priced & VFM)
xDrive (Rear biased weapon)