ive heard they help with wheelhop more than spin, i think but i could be wrong that someone said he actually spins more, but the car has no more wheelhop. he said he definitely saw a benefit though.
I can see them reducing wheelhop, but at the expense of full articulation. They claim that they don't "bind" but that can't be entirely true since they don't move through motion arcs that are identical to the arcs of the stock arms alone...
More than anything, they reduce fore and aft movement of the the control arms (movement that is allowed by the "play" in the stock rubber lower control arm bushings).
Stiffer springs and shocks will only help as far as they can by limiting weight transfer to the rear, which isn't a lot (unless you get CRAZY STIFF custom rear springs).
I think they'll help, but they certainly won't be a "magic bullet."
