Poly bushings will last longer and are more stable when side flex comes into play because they don't compress as much. Rubber ones are softer but poly ones still absorb vibration and impact so I don't know how much of that difference would translate to a "noticable" better ride. The elements or grease and oil don't effect the poly ones like they do the rubber ones. And I would think the rubber ones are noisier since they create more friction against a surface and then squeek, whereas poly slides better especially when lubed, which they always should be.
So there's pros and cons to both. Weight them yourself, but I choose poly.