As with any lift kit the RR kit has its pluses & minuses. A lot of guys on this board favor the long arm kits which has its own set of quirks but many are outweighed by what you gain with them. Again this goes both ways, many dislike them.
IMO the best bang for the buck is the RE 5.5. I friend of mine just built up his 2001 with this kit and 2 inch blocks and coils spacers to fit 35's. The blocks and spacers don't void the kits warranty, in fact they were purchased from RE at the same time also. Ideally blocks and spacers aren't the way lift to 7.5+ inches but my friend wanted back for the buck. He used the left over money he saved for Bushwackers, ARB bumper & 35" tires.
If I had to do it again, I'd buy the RR kit's separate pieces which are now offered through Jeep Speed. The sub-frame, arms, coils and trac bar are all top notch pieces, everything else I'd replace. In fact, I all ready have. Heims on one end of the control arms are fine but I think a bushing at the other end makes more sense. The trac bar comes the way, why not the arms? Tera now makes a direct bushing replacement for the SJ heims. I got the first set from Tera's warehouse. They didn't even have a part # assigned to them yet.
The rear springs are the next to go. I see now SJ has a better miltary wrapped design like Alcan, but it's currently only available for the YJ. I bet within the next several months the XJ kit will get it too.
Good luck with your decision & get as many opinions as you can. I didn't, and my depleted bank account proves it.

-Todd