Everybody is dead on with the comments above.
I own both E90 325i, and 328i ZSP ZPP Auto. There is a noticable difference in the two. My biggest gripe, is how smooth the ZF transmission is on the 325i compared to the 08 328i with the GM trans. I don't understand why BMW decided in 06 all autos got the ZF trans, and in 07, 08, 09 only the 335i gets the ZF trans. I also have a dinan intake and exhaust on my 328i, and it feels faster and more repsonsive than the 330i I drove last November. The 330i has a touch more low end grunt. Awesome car, they should have continued building the N52 with a 3 stage intake.
In closing...328i and 330i stock are pretty darn close, and most will never tell. BMW did a good job with N52 updates. I would still rather wait until the Bavarians perfect the new TT I6 engine. For now I'm very pleased with my NA I6.
I'm taking the transmission out of my wife's 325i and putting it in my 328i