will it be faster than my old harleys? faster than a honda shadow?
The Shadow line features motorcycles with a liquid-cooled 52-degree V-twin ranging from 125cc to 1800cc engine displacement.
IF you have the patience to make the engine work with the mods, and know how to drive the bike, it could be faster.
You will have to learn to use the transmission to keep the R's in the power band, as it doesn't make famous torque at low RPM. You're gonna need ear plugs with those open pipes, or plan to learn sign language in everyday life.
My guess it that you will just want to twist the throttle to scoot, and all the Harley's will walk away doing this same sort of thing. If you use your left foot right, you can keep up and maybe go around them. With less weight and prowess you can beat them in a drag race (I did so with a 550 and a slipping clutch). But, I also didn't admire the Harley guy's riding skill. He did stop razzing me about my "little" bike, though.