I have an 02 rsx which used to have dusty brakes (wash my cars weekly and about 350 miles/ week). Upgraded to Brembo brakes new pads...dusted little during street driving, A LOT on tracks.
With the 335is, I can go a week without ANY noticeable brake dust. The brakes do not squeak in anyway, or feel mushy-although it could use a BBK with the extra weight from the e93...maybe some brembos are in order