I have had a chance to see this exhaust up close and hear it personally. The only fitting issue I know of is that the pipe comes so close to the sump that they had to line the sump with heat reflective tape so the heat from the pipe didn't transfer to the sump. As far as weld quality and sound...it is pretty amazing. With 1 baffle it is way too loud for the street. We are talking permanent hearing damage without ear plugs. At idle, it sounds like the devil got involved with the sound design. Very mean sounding. I considered this exhaust until I heard it and realized I would be spending big $ on tickets.
I have never been a believer of bolt on exhaust and not tuning winch is what this owner had to do because the tuning that was tried made it run even worse, so they settled with the factory tune. At over $4k there should be a tune to go with the pipe that makes it exceed the factory HP and torque. Sad to say but, without the proper tuning, you are going to lose power with a completely free breathing pipe like this. Not to mention less torque. Been there, done it.(other bikes)
If sound is where it's at for you...this pipe will get you there. You will definitely be the standout in the crowd with the looks and sound, but don't expect to out run a stock 1199. just my 2 cents.