i have heard that the perfex lift kits lift a 4wheeler about 1 1/2 but i could be wrong. i have also heard that they are alot better than regular lifts because they are adjustable. i know what you mean about rough riding i had a lift and 27's on my old rubicon and it was rough, if you just put your lift on you are proubly not used to it, it took me a month or so to get used to mine. also before you take it off and everything try letting air out of the tires, i also did that and it made a difference.
-Aaron