They ride and flex great. They're a little stiff at first, but I didn't really 'break them in' right away on trails and torqued the frame and shackle bolts at max spec. If you torque them down around nominal or minimum spec, they should soften up a bit quicker. You can also park your Jeep on top of something to flex it out overnight (properly blocked of course) to soften them up quicker.
It's probably the best overall spring under kit you can buy. The only thing it doesn't come with (aside from shocks, unless you choose that option) is a SYE/CV kit, but that's only because of the difference in transmissions and axles found in YJ's and the variety of options for SYE. If I weren't planning on doing an SOA on my next YJ, I'd definitely go with the RE XD kit again.
Just a few things about the kit:
- The aluminum shims suck and so do the centering pins in the leafs. Get steel shims and grade 8 bolts to replace the centering pins before you install the leafs. It'll save you time and effort down the road. Don't even bother installing front shims, the driveline is long enough to accomodate the slight increase in angle.
- The track bars are worthless. They provide a relocating bracket for the front, but I just left it off and didn't notice any difference in the handling at all.