I actually own a 335i. Great car. Unbelievable car. Though I am almost bought the Audi...My take:-Audi has a nicer interior-Audi has a nicer exhaust note-Audi has better styling when stock-335i has better acceleration. Flat out, it is only marginally faster than the S5, but in day to day driving (like passing on a freeway) the 335i is worlds faster-The 335i handles better in the summer. Audi handles better in rain/snow. I live in FL most of the year so... BMW wins for me.-The 335i has a more livable backseat (I've had guys 6'2' back there no problem).-335i gets much better fuel economy. In town driving is probably comparable, but I'd like to see the Audi get 29mpg on a road trip (that's what I got on a drive to TN)-Once styled with the aero front lip, mtech sides, and nice aftermarket wheels, the 335i is just as stylish as the S5.