Pump action one is pretty good. Even better then the seme auto jackal. Pump does loads more damage plus it's awesome hearing the pump action between shots.
But be careful... Last night some dude kept dodging my shots between the pumps lol.
okay

btw, mobility enhance (for running and gunning)
-OR-
Weapon Pro (for faster reloading?)
Depends on your play style, how good you are at aiming, and what weapons you use. For me it's weapon pro

i tried it with mobility enhance, i liked it when i had to stalk someone till i'm close enough. I'll try it with weapon pro tomorrow because the pumping is too long in combat.