I'm looking to add a 3 inch catback to my STi with Helix catted DP and want some opinions about these systems...Bosal/SPT, Greedy EVO2, Borla Hush. I'm looking for something fairly quiet with just a little more rumble than the stock system. Can you get the Borla Hush with a single tip or just dual tip? I'm interested in just single tip systems to keep a fairly stock STi look. Unfortunatley I haven't heard any of these in person, so I'll rely on some of your opinions to make a decision. Thanks for the input!