i have hpa setup with 392/616 swift springs. it's a bit harsh but not annoying. handling is great and it could be comfy on freeway. if i compare the ride between that to my E70 X5 with adaptive suspension with the "Sport" on, it's not a lot stiffer than the e70, just a little more "solid" and less frequency. very minimal body roll. i had my wife and my daughter (she was 5 months old back then) sat in my car and both didn't show any discomfort.
depends what kind of ride do you need, talk to Harold and he will be gladly to fit the right spec springs for you.
E90 335i TiAg *STOCK*
see my garage for mod list..
E70 X5 SGM *try to stay stock* :/