i heard from drivers that the xcelsior buses the hybrid versions on a hill they will slightly roll backwards if u dont catch it it may roll into a car behind it. community transit from out of everett washington has the 2011 xcelsior buses.
Xcelsiors maybe Overrated but I'll rather take and Nova LF that over Boring Ol Gillig Advantage/BRTs, As far as Sway, All New Flyers been doing that, even Older D40LFs, like ones here at CTA.