I have an 04 Rubicon and I have a 2.5 Skyjacker lift right now. I bought it with it and do not like it and have always wanted a bigger lift. I have a solid steel Warn bumper and a winch on the front. Ive noticed that on the front I don't really have a lift because all that weight really sags the front. I was debating between the 4 inch zone kit or the 3.5 Rock Krawler kit. I've seen some reviews saying the zone may sag over time while the RK will not. Just trying to get opinions before I make my decision. Ive only heard good things about the RK kit though. It is just a little bit more money.