An OTT lift places all the stress at the top of the strut, also the way it is designed if you do not have the bumpstops in place it will blow your struts in no time at all. This kit mentioned here does include the bumpstops, which is good because most do not, but it is still just a band aid fix to make it work.
On the KJs with an OTT the struts would fail sometimes in a few thousand miles, and also the UBJs would go. Of course thats how I got my ARB bumper so cheap, college kid, limited budget, installed OTT lift, struts went out they replaced them, UBJs went one broke driving down the road, his Dad removed everything and sold it to me, telling me that there was no way to lift a Liberty
Only way that someone got it (an OTT) to work was with longer struts from a mini van and lots of bumpstop, but he never offroaded any at all
Its cheap to do, but I guess my point is do you want to spend the money now for something that you may have to replace with something better later on if you keep yours long term