Akrapovic fitted on 2013 glee 650 proper sound with baffle in probably too loud without but never tried, is it faster I doubt it. Does it affect nog nope still the same...it's really just a very expensive way to make your glee sound like a motorcycle should,in my opinion the standard exhaust sounds like a sewing machine & is a disgrace.I don't want to wake the Neighbours or shatter windows but it must sound proper. It's really just an expensive lolly pop stick in the spokes,but there's no denying the build quality and fit & finish.