W.Knight, i put an ooen filter on mine a week or so ago and it sounded great even on my stock exaust, i dont think i would want any wxtra noise from a sports zorst, it was way loud enough.
I even found i couldnt help myself twisting the throttle and doin fake gear drops as i slowed down for lights and bends etc just to hear the rip off it lol. Had to go back to stock airbox for now till i get paid and find some bigger jets tho, the 110 was too lean, reckon i need a 112 or 114 jet !!!
Didnt notice any improvement in performance but that prob just down to it not being jetted properly, hopin once i get the bigger jet in amd try again it will improve. That sound was nice tho none the less and it looks so much cleaner without that plastic airbox so its prob worth it just for that.