My good buddy has the ZJ version of this kit on his rig, and I've got a good amount of hands on wheeling with it, and was present for/assisted with a good deal of the installation of it. I know its a ZJ, however the kit is almost identical aside from the fact is has 4 more links off the back of the crossmember.
The "company" is a young guy named Ty who is a college student putting these out on the side. He builds damn good stuff, but is sometimes hard to keep in sync with. Understandably so though. He puts a lot of time into the kits, and for the most part, it shows. They are overbuilt and hell for stout. Good luck breaking any of his parts. The kit that went on our local built ZJ was a bit off for fitment in some spots, but wasnt too tough to massage to fit correctly. As of a couple months ago, he had only actually produced about a half dozen kits, and a few were more of a prototype than actual production.
As mentioned, a little bit of work was required to fit the kit such as drilling/clearancing some holes to make pieces line up. The hardest part was in fitting the front LCA's. The uppers mount off them in a radius arm style (like RE, Fabtech, etc) and the mounts were a little off in their fitment to the arms. The brackets had to be cut, and rotated inward just a little to get the uppers to line up correctly with the mounts on the front axle. However, that WAS a kit that was shipped out a couple months ago and that issue was brought to his attention and may well have been cured by now.
All in all, its a damn stout kit and is very affordable for how durable it is. You'd be hardpressed to damage the crossmember, bellypan, arms or any portion. It wont ramp a thousand on the RTI, but does flex pretty well with the correct length shocks and brakelines. The pan does hang down a bit low, but I personally believe it is worth it. You may lose an inch to an inch and a half on breakover, but for the amount of steel that is under there, and for as stout as it is, I'd rather have it than some of the "higher clearance" kits that arent nearly as rock-draggable.
Of course, this is a 4 linked ZJ, so your results will differ, however you can judge the front end flex some...
If I was going to build another XJ that was going to see nasty rocks day in and day out, this is the kit I'd go for. Hope that helps!!!
Nolan