A close friend had a '99 TJ (Sahara model), only had a 4" lift and 33's, but overall a pretty descent vehicle...(if you like jxxps stop reading here)...he did amazingly well offroad, had a ARB in the front diff, Dana 44 in the rear.
It wasn't bad to ride in, on the highway way nicer than say my FJ40, pretty good power (he had the 5sp), he drove it like a maniac, slid around corners, dropped the clutch from 4000 rpms probably 3500 times while he owned it, so it took a ton of abuse.
About 40K miles his t/c started making this horrendous noise, come to find out the chain in it (the NP231 is a chain-driven t/c, also the Toy Tacoma is too, so that alone is not a huge problem) had stretched, either from his awesome driving, or maybe he wacked it and the fluid leaked out, I never got a straight answer about that. (I know he wacked it hundreds of times, but whether it leaked or not would be the question).
He split the t/c, replaced the chain and all was good again. Then his rearend started making wierd noises, it was a trakloc or some crap, he pulled the rear cover and found pieces of his spider gears, he had broken about 2 teeth of two seperate ones. This was the Dana 44 remember, he removed the broken pieces and kept driving it.
He finally realized it had to go, at about 50K miles it started to feel like a really old vehicle (mostly from the way he drove it though), suspension was shot, loose, piece of junk. He neogiated with a dealership that he would pull out the ARB in the front and then trade it in (he was leasing it, so had it coming in his backside no matter what he did).
I helped him pull out the front ARB carrier and put back in the factory open diff. I could not believe how much wear was on the open diff, it had only seen about 10K miles before he had the ARB installed, it had visible wear. It had MORE wear than the spiders gears on my FJ40 had with 135K miles on them!!! The design on the front is annoying, it's not like a Cruiser at all, there is a large nut at the end of the axle, which always gets rusted, so we ended up removing the spindle from the control arms which lets you pull it out, only held on by three bolts, which is fine, but kinda a odd/cheap setup in my opinion.
Overall the Jxxp was a descent vehicle, my friend totally trashed his, and never put in a tail-shaft kit (jeeps do not have a flange on the driveshaft, the u-joint is shared inbetween the driveshaft and the t/c or rearend, definetly a cheaper approach, and impossible to put on a CV jointed shaft unless you put in a tail-shaft conversion, the new Rubicon comes with a tail-shaft conversion already done). I'll admit TJ's are cute, having a convertible that is 4wheel drive is cool, really nice college chick vehicle, but as far as reliable, a 'nice' vehicle that is very solid, not really comparable to the Cruiser.
They are way different in size, even my FJ40 was way bigger than the TJ, if alone not a big deal, but factor in a wife and kid, and a few camping items and you got no space at all...the TJ is definetly more nimble than a 80-series offroad, no doubt about that, lighter, takes less power to get up stuff...I have seen several with 35" tires that wheel HARD and never break anything, mostly because they don't weigh alot...but their axles are amazingly strong, ofcourse you could break if you tried, but the drivetrain (as far as 4wheeling, not high mileage) seems fairly descent, atleast from my limited experience.
Good Luck...
Mark Brodis