I wouldn't say it's bad, per se, but its not complete. It's a budget lift to the max, and for what you pay I feel like you'd really just be better off with a Teraflex BB or something. I'm in the middle of swapping my 3" Zone kit for a 2.5" Rock Krawler just because I started to become wary of the lift after I learned more about my Jeep.
Instead of extended brake lines, or drop brackets, the kit comes with a brake line drop for the rear but for they front they tell you to cut the tab off your brake line mount and just screw it into your frame further down... Seriously? You couldn't just supply a new bracket that would cost maybe a buck in steel? The parts are hecho en Mexico. They might not be terrible quality, but I'd rather buy American. After about 2 months of having the lift in plus new steel bumpers I got more sagging than I'd like plus a serious front rake. Instead of quick disco swaybar links or even new links they just have you take your old rear links and move them to the front. Not a bad idea, but again, for being a "lift kit" it just seems like theres too many corners cut.
I just got nervous and decided that with how I plan on wheeling my Jeep, I'd rather have a more complete kit that is tried and true from the Jeep community. The Zone kit is a good lift for a mall crawler but not something I would wheel too hard on. And if your Jeep is a mall crawler I'd probably just go for the Teraflex boost and keep the rest of it mostly stock components... Instead of swapping it out for a barebones kit.