I considered both of those kits, went with the Clayton's. I haven't heard any "bad" things about either, but I was told that the RE kit can interfere with some rock slider mounts. I will say that the Rock Krawler rear leafs that used to come with the Clayton's kit are garbage, mine turned from "U"s to "W"s in just one year. I have been told that Clayton's no longer uses the RK leaf packs, which is a good thing.
The price diffrence is negliegable, IMO. Do a search here on both kits, you'll find tons of opinions.