Speaking from experience, the RRO spacer lift is pretty much worth it's weight in scrap. I ran one for a short time and had issues. The amount of lift wasn't a problem but the fact that my lowered shocks would top out before the uca hit the bump stop. I'm running an OME set up now and had to keep the rear spacers because I add two top plates to the front. It sits at about the same rake as stock which I intend to change some day but it works pretty good the way it is.
BTW, there is a crap load of information on lost jeeps about RRO and lifting Libertys in general. If you look around you'll probably figure out why they stay away from these sites.
2010 KK Sport, Detoures Knucklebone & backbone, smittybilt XRC 10, rigid led lights, R/L sliders & rack, cb, EMT2, R/K 15x7, OME, JBA, mopar skids & hitch, headlight covers, 4.10's and TruTracs