the main advantage IMO is the Poly doesn't rot away like the rubber. i ran poly's in my 68 Charger for years with no issue. But that was before they were blackballed for some reason. The other comment I'll make is we seem to have forgotten how to make rubber suspension components that last. in my experience i have seen bushings and grease boots start to fail in 3-5 years
i have seen rubber bushings develop cracks in less than three weeks ! they were the moog brand, and that was almost 20 years ago. tie rod and ball joint boots from moog as well that long ago.
this is why i haven't liked that brand for a very long time !
if one has access to a lathe, delrin is a very good material to make bushings out of. way better material in my opinion.
just my personal experience as a machinist with over 50 years experience. your mileage will vary.
