My QS is as smooth as butter, but particular. It will be a little jerky if I'm not above 6K RPMs or if I'm not accelerating. First gear ratio is very torquey so I tend not to clutchless upshift out of or downshift into it. I didn't own the bike when it was completely stock, picked it up modded and flashed, so I can't tell you if anything changed post-mods, but I wouldn't doubt a flash improves the "smoothness" as most flashes do.
When in doubt... send it!