I think what Bluesyes is trying to say here N52unded is that this topic has really been beat to death in the forums. One simple search will spill pages upon pages of information about this subject...everyone has an opinion...
I did the same research about a year ago and read through these pages upon pages of information. In the end there are a couple of questions that commonly run through all the posts.
1. Do you intend to track the car for fun days.
2. What do you want in your car.
The simple skinny from what I have read is this...yes a lot of people think it is a very worth while upgrade for the 328. If you can get the parts cheap. Some E-Models can actually run the rear 335's as well...I'll post a couple links below to threads I thought were very useful when I was looking to do this upgrade.
In the end I went with the BMW performance upgrade kit. I don't track my car, I don't drive it hard...it is a summer car only but I wanted to upgrade my brakes. Overkill? Sure, I totally agree. But...my money...my car. Constructive criticism always welcome.
Upgrading brakes on a 328i is a "never go wrong" choice for an improvement IMO. Your money, your car. But I don't think you will be unhappy on this one...
All the best
VMX1
https://www.e90post.com/forums/showthread.php?t=1119790
https://www.e90post.com/forums/showthread.php?t=311157