I spent 6 months looking for an AWD Sport Sedan (live in NE, lots of snow and hills). Really didn't love any of them. Finally decided on BMW530XI over InfinitiM35X and LexusGS300. Went to buy 530XI and saw this at the dealer. One drive and I was sold. The car has the excitement that all the others are lacking. Acceleration, cornering, grip, etc... without the "ego" factor - understated "stealth". And the interior is much more functional than the BMW. Electronics (NAV, SAT Radio) work flawlessly! Recaro seats are perfect for a comfortable, but aggressive drive. This car competes as a realistic option for more than just the M3 it is usually compared with. I couldn't be more pleased!
Engine - the performance is awesome and the sound is incredible. Flawless handling and cornering. Confidence of AWD. Incredibly easy Nav/Stereo/SAT Radio interface. Seats (shape, adjustabilty, leather quality). Unexpected trunk capacity. Real cupholders, convenient pockets, drawers. ABS Wheels
Slightly bigger backseat. Bluetooth. Voice Recognition. Keyless entry. A touch less jiggle over bumps. Better fuel economy (but worth it for the power), or at least a bigger gas tank. Ventilated/Cooled front seats.