Doesn't the roadster have options w/regard to 6th gear ratio? Thought you could have "sport" 6th, as appears to be standard on Rocksters, or an overdrive 6th? "Sport" is great for instant go in top, terrific overtaking pull;; without a down shift, but is limited to continuous cruise at 140 km/hr. (gets a bit of a buzz up at 150)
Both bikes could have overdrive or standard 6th gear as a no cost option. When people moan about the lack of go in the overdrive 6th I remind them that there are 5 other gears and there is no law which says you have to stay in top.