I have a 335i with sports package and at one point I drove a 328i without the sports package (loaner). The 328i was definitely softer than my 335i. Like another poster said above, the main difference in stiffness will come from the sports package. Having said that, I do commute on my 335i and love it. I gave
a ride home to one of my coworkers lately (he has an RX8) and he literally said ...