I added a pipe today
It doesn't fix the melted turn signal problem - actually makes it worse
The shop re-mapped it with the Akropovic map from KTM. First impressions - the map is the best part of it. Seems to have removed the partial throttle hunting (no doubt due to leaness) and overall, the bike seems smoother, with less vibes.
Its also running cooler and my ankle isn't getting hot like it did with the stock pipe. I don't think its changed the power characteristics, the bottom is still not as strong as I would like but completely removing the airbox cover seems to be the only way to improve that.
And what about sound levels? I'm glad you asked. Idling its a bit gruffer than the stock pipe but actual dB I would say no difference. On a steady throttle it might even be quieter than stock. However, getting on it is definitely louder and the top end is a dB level I'm not super comfortable with but its not Harley obnoxious. You can definitely sneak through your sub-division without pissing off the neighbors. I might have a buddy of mine machine up a quieter insert even so. The loudest noise was on trailing throttle and the turbulence from the messed up turn signal - this pipe is moving a lot more air than the stock one.
One last thing I noticed was a noticeable change in weight. Now this is just seat of the pants and I'm hesitant to jump to a conclusion but my gut feeling is a lighter bike, with a more balanced feel. YMMV
Overall for the cooler running and much improved fueling I give it
I also installed the 15 tooth counter shaft sprocket. No noticeable difference I could tell. Might go to a 42 tooth rear and see what that does.