I had Redline (here in Aust) modify my stocks. Removed baffles using the broomstick method, left the servo valve open, welded in spark arresters etc. More than happy with the exhaust note and flow. Did this before Dyno, so no idea on performance gains, but it is now loud without being obnoxious. (the broomstick method can be found on YouTube).
My dyno info can be found in one of my posts if interested.
Once you get accustomed to the new ride, I can highly recommend looking into the Evo Star Shift (or similar) and the healtech quick shift. I have no affiliation to these products but found it to be night and day when upshifting.. I did a little write up on this too..