For now I just took off the muffler and put on a vibrant resonator ( bought at modernperformance.com ) in its place with a 2.5inch tip. Has a great deep sound at half to full throttle that does not cause a ton of droan at highway speeds. Slightly louder then stock at idle but not much, only when you get on the throttle. Turbo seems to spool up a little bit better. Right after I did that I took a 3 1/2 hour trip in it and never got anoyyed with it. Believe it or not I got a little better gas mileage on the highway. Deff. worth it if you are just wanting some sound added to your cruiser.
In two weeks I'll have my exhaust system ready to be installed that consist of a mpx ( modern performance ) 3inch o2, CHQ 3inch dp with a magnaflow cat, quick time cut out after the CAT, 2.5 piping routed to the side with just a resonator to quiet things down a tad
PS I have just one 12'' resonator on it. Two might make it just as quiet as stock. A slightly longer 14 to 16'' resonator will make it less loud then a 12'' Let me know if you want a Sound clip. Ill send you one of my 05 HO.