I installed the RK stock mod package from Marcus a couple of weeks ago. I've had it out wheeling twice for about 8 hours each time. My thoughts on the lift:
-I went with the Fox shocks. I'm really happy with them. On the road, I think it rides better than the stock Rubicon suspension that it replaced. Less body roll and the bumps are smooth. In my two door, I get less side to side rolling on diagonal bumps in the road, where each tire would hit at a different time. All that and it's less jarring, plus it controls the rebound a hell of a lot better than stock.
-Now the fun one; offroad, even on my stock arms, the difference is pretty wild. The flex I get out of those triple rate coils and the shocks is awesome. My 2 door is pretty light, so I did get more than the advertised 2.5". With the front disconnected, it seems like the coils just want to stretch forever. I did get into some sections that before, would have thrown the Jeep way to one side before. But now, it stays relatively flat and planted. I'm thoroughly impressed with the performance of this lift, even on stock arms. For the money that I spent, it was worth every dime. Wheeling is really enjoyable whereas I am confident where I used to second guess. I can't praise those coils enough. Plus, the track bar is super solid and the rear relocation bracket is certainly stout. Here is a little stretching that was caught on camera from one of those days out
The biggest limiting factor I have now is actually my rear sway bar end links. In the picture, the front has way more than the back, well, they are why. I'm going to rectify that soon. I didn't realize how much lift I was going to get with it, so I have no worries about adding some weight, reasonably, to my Jeep. It makes my 33x12.5 inch tires look kinda dumb now.
My vote is the lift, install, enjoy and save for the welder over the winter. I thought that the kit was going to leave me wanting for a lot more, but I'm actually happy as is, save for tires.