I have the RB3's (haven't installed them yet, but will). I think RB3's design, with nesting halves that allow for a flange on both ends of the bushing, is better. That said, RB3 is using black Delrin while Garage Products is using oil filled UHMM. UHMW is more wear resistant to grit and grime, being up to 20 times more so than carbon steel. However, Delrin is structurally stronger and more creep resistant. I've used both, but not sure which would be better in this application . . . though I'd tend to lean towards the UHMW.