>>28656276 (OP)
I'm driving a 330i with the B48. Bought it a year ago.
Before I bought the car, I also had to decide between the 330i and the 340i.
My uncle, who already owned the 330i (and still does), let me go for test drive. The car is surprisingly fast.
Until then, I had a E92 328i (RIP old buddy ;_;), but the new 330i felt way faster.
The interieur also felt high quality and my uncle never had any problems with it, despite the high mileage.
After that, I had to compare the prices of the 330i and 340i and in the end, I decided that paying 15k EUR (~17k USD) more for two more cylinders and more power isn't worth it, at least in my case.
One of the reason being that I live in the city and my surroundings are not wide, open and long roads like in the US and there are a lot of speed camera traps. I guess owning a 340i in the US makes more sense.
The other reason was that I found an online listing for a 330i, very well equipped (M package, M Performance with LSD and so on), with low mileage and for a cheap price.
Thank god mine is RWD, it slides nicely and I can do some drifts at night. AFAIK the US only gets XDrive, which is a shame.
Also, the engine has a VERY high torque output, but the turbo lag is kinda bad.
It can easily keep up with the hot hatches around here, like the Golf GTI and the i30 N (yuropoor version of Elantra N).
Feel free to ask me more about the 330i.