Heck, I put some stock weight ones in my S200 and the difference was notable.
Just going to get around to pulling them for a peek and a housing cleaning in the next week or so, but they went a long way towards killing the dead spot in acceleration along with fatter jetting.
Overall I'm a fan, at least on the S200, the other similar scoot I've worked on was the HD200 which was fine with the stock rollers, so can't say there.