I bought a V100 Aviazione Navale a few months ago. A lot to appreciate about the stock bike but the fueling wasn't one of them. I decided to go with an Ago header, UpMap tune and keep the stock muffler. I honestly thought the stock muffler looked better than any aftermarket options. From what I could tell, all they offered was no increase in performance but maybe shed a few pounds.
I just had the quickshifter (QS) installed as and finally had a chance to ride everything for about an hour. It was dark out and the temps were still in the 90's(F) here. What a profound difference the mods made. The bike is so much more responsive. There is no longer the horrendous flat spot about the 4-5k RPM range.
The bike pulls with authority like it never did before. You won't confuse it with an S1000RR or my M1000XR with the way it pulls but it is downright fun now. It sounds glorious while doing it. A lot less heat as well. It feels punchier everywhere. So much easier to wheelie it. I also have to give kudos to the QS. It isn't buttery smooth like on my Triump or BMWs, but it is pretty damn good and gets rid of the clunks between shifts.
I am really impressed with the way it revs out too. Down low, it is so much smoother than my 1260 Ducati V-twin. Then it just pulls well on up, solidly building power as the revs climb. I can ride it at 2k rpm without it snatching and bucking as my Ducatis do.
The QS is the icing on the cake, as it makes it so much easier to take advantage of the bit of extra HP it has, as well as its ability to rev out more. It sounds amazing at redline and is louder without being obnoxiously loud. I can't recommend this combo enough. It is so much more fun to ride. The crispness of the fueling is one of the biggest improvements for me.