I was able to get some 1 on 1 time with an 07 335i sedan 6 speed last night. The car had about 10K on it and was fully broken in. I won't waste too much time explaining the fit and finish because it is what you would expect from a BMW. I did not like that I couldn't easily find the button for the heated seats, or master unlock for all the doors.
The ride was comfortable and relaxed but still tight. There was no sway or excessive play in the lateral dynamics of the chassis or suspension while driving. The steering was surprisingly uncamunicative. It wasn't too light or fluffy but it wasnt as tight as a M3 or a STi or a S4 or any Porsche. The brakes were a bit grabby, not as grabby as a GLI (1.8t and 2.0t) but more-so than the progressive brake feel you find in the other sport brake setups out there.
Power...... There is plenty of that.... Everywhere! It's smooth power and torque, and it's always there, everywhere, in any gear at anytime. The only time I found myself waiting was after a shift. It was like driving a stock STi. I guess some drive-by-wire systems are like that. From what I have read, I think solutions for that issue are available from Dinan, Vishnu, and AA when you flash the ecu or add a piggyback system. Turn the DTC off and you will spin anywhere through 1st and spin easily while grabbing 2nd gear. Part of DTC was still active because it has like a 2 or 3 stage disarming. The car is deceptively quick. Easily faster than a modified 4-banger on the highway. It does not stop pulling.... ever! I can see why guys who have modified them with an exhaust and piggyback are able to pull away from modified M5s and M6s.
Would I buy one??? H3LL NO!!! Although the 335i is a good car, it's not a great car. It doesnt give you the tingly feeling you get from driving an mk4 R32, B6/B7 S4, e46 M3, or anything else in its class. It doesnt stand out in a pack like those cars mentioned. It looks like any regular BMW. The overall driving dynamics are like any other regular BMW. I'm sure it would be fun on a track, considering in stock form it lapped the Nurburgring under 4 seconds slower than the E46 M3, but on my favorite winding roads here in CT, it won't cut it in the fun department. I drove a B6 S4 immediately after that and although the S4 was noticeably slower, it felt like a better sports car, it looked like a better sports car. If Audi could make something that was as responsive to modifications as a 335 while maintaining the sport factor that they currently have, I wouldn't own anything else.
To sum it up, the 335i is a great secondary vehicle. It is a great primary vehicle for my girlfriend or any guy's significant other but I would need more sport. It needs a sportier suspension, a limited slip diff, and more communicative steering. If it had a limited slip differential and was as responsive as an M3 while also sharing the M3s suspension, it would be the ultimate luxury tuning vehicle under a 996 or 997 Turbo. But then, BMW wouldn't sell any of the upcomming E9X M3s due out here in the spring.
This vague review is from a refined performance perspective. I don't just mean power. I am not talking about all-out sport. I am referring to the total package. If I lived in Florida where the roads are straight forever, and was looking for something fast, a little sporty, and very low-key, this may be the vehicle for me. But those true automotive enthusiasts need more.