Just ordered and installed Witchdoctor Baffled Muscle Mufflers.  I had OEM mufflers on.  The product is excellent, the sound is excellent, low and mellow at idle & cruise but comes to life under throttle.  I don't like "loud" that's why I went for these.  My only comment is don't go by the "1 hour" suggested install time on the website.  I'm not a mechanic just a backyard tinkerer.  Was not hard, but whole thing took me about 3 hours.  Hardest part was removing and reinstalling the plastic valence under saddlebag.