This is the only lift kit I've ever installed, other than mix and match stuff with rubicon springs & spacers. This kit blows away the mix & match stuff. The flex is good. Had some rubbing issues so I added 1" body lift to clear my 33's. Now they tuck nicely under the flares. No sagging so far. I'll update if anything changes. I'd say a this is a good kit at a good price... but I did get a great deal when it was on sale
After running this for a few years and several off road trips, I can say my stock front LCA's have had the crap beaten out of them. I've had to replace 3 times (2 driver, 1 passenger). I'd definitely add adjustable LCA's to this setup. I also replaced the sway bar discos with another brand quite awhile back because the kit's were junk. I had to replace the TRE on my adjustable Track bar too. The springs seem to be holding up, no sagging that I can see. I'd recommend to get something more robust if you plan to do much wheeling.
Now I can be more blunt. Don't buy this kit if you plan to go 4 wheeling. You'll eventually end up replacing all the parts with better quality. I haven't done a TON of wheeling with this kit, but it was always on difficult terrain. I replaced the TRE on the Track bar awhile back & now I discovered the Bushing is shot. I already spent $35 on a Moog TRE, only to find out Full Traction sells a kit- replacement TRE & Bushing for $60. They will separate & sell the bushing alone for $35 (plus shipping). However, I won't be wasting my money because it will just fail again. I now need to look for a better quality adjustable Track bar. So basically all I will have left on my Jeep from this kit are the springs. I'm not upset I bought this kit, I didn't have the money for something more expensive at the time. But by the time I'm finished replacing parts, I will have easily spent more than if I bought a better kit from the start.