The dissadvantages outway the advantages by a long shot. I haven't tried them yet so maybe someone on here will have some input but the trailgear greeper joint shackle mount seems like a much more practical product to me.
For the reasons stated above. Except I have never in my life actually seen or met anyone who has had a shackle open up on hard braking. I had them on my cruiser way back when and they worked just fine and never opened up when I didn't want them to but I have seen other that have opened up on hills. Coming from someone that has owned them I don't think they are nearly as bad as what people say/think.