I had the 4" version of that lift. I both rear shocks blew in less then a year and it had some bad shimmies.
Swapped springs out for RK 3.5" springs and bilstein 5100 shocks and added a synergy drag link flip and it now drives like it should. I pretty much replace almost everything that came with the lift.
it now rides smooth and steering is vastly improved with the flip kit
When it was all working it wasn't half bad but the stuff didn't hold up long enough.