Other than a bit of unloading which a limit strap in the center of the axle mostley took care of it actually has served me well. BUT if I had it to do over I would have just linked it with coils or coilovers.
Disadvantage:
Unloading,
Schackles hit everything,
If the "Goofy leaf" breaks , your in trouble,
Advantage:
Quite a bit of droop for the rear.
So, imo, if your looking for more flex youd be better off linking it or getting a set of alcan's.