suspension upgrades

Recently got a 330xi. Love the car overall, only like the suspension. It's too high, too soft, and has an astonishing amount of roll for a BMW. Anyone out there upgraded their suspension and had a good/bad experience that they'd like to pass along? I'm considering a Dinan stage 2, but haven't made any decisions yet. Also, has anyone had any warranty experience with the suspension upgrade that they'd like to share? Any bad experiences in terms of how it affects your BMW warrants? Thanks in advance.

FYI, used to own at A4 1.8T. The 330xi is superior in every regard other than the suspension and the awd. The Audi AWD really is better.

The only problem with DINAN is that you pay ALOT just for the name... you can get the same amout of performance at a TON less by going with some H&R's, and new sways.