The Rubi is great if you're really up for driving a Jeep. I had an X, and now have a Rubi. Wheeled both of them significantly. While the stock Rubi does many have technical advantages over the stock X, the biggest difference offroad is the maneuverability due to the wheelbase. The TJ will run circles around the X. You'll probably spend half as much on mods for the Rubi, Jeep parts are cheap. A big determining factor is "what's the weather like there?". We've had a very nice summer here, and I've had the top down and doors off about 80% of the time. Feeling the sun on your face and wind in your hair is awesome, and no other vehicle can compare (except perhaps a bike). Plus there's the chick-magnet factor (sorry soccer-mom X-owners). :p As far as reliability, my Rubi is over 30k after 1.5 years, and hasn't had any problems (except a front wheel that's currently wickedly out of balance). I had more problems with my Xterra than I have with this.

Now the bad part is that you have to wholeheartedly accept the fact that it rides like a Jeep. Its quite a rough ride, and insanely loud with the soft top on. The stereo can keep up, but its not exactly audiophile-quality. I have no problem taking road trips across the country in my Jeep, but you do have to pack light. Any camping trip with more than 1 passenger is pretty much out of the question. I have to leave my two 30lb dogs at home when camping with my girlfriend. A trailer for gear is always an option, but I haven't made it there yet. Roofracks are also a possibility, but since the aerodynamics are already that of a brick you may not want to make it worse (plus you don't want to f* with the already high CG). Gas mileage sucks (although my 2001 X did, too). I get about 14.5 mpg, consistently. I don't know what the guys in the new X's are getting.

If you want something insanely fun to drive, and like the elements, and/or plan on a lot of offroading, get the Jeep. Otherwise stick with the X. Personally, if I was looking at an Xterra-type vehicle, I'd bypass it for something with less macho-image and better fuel economy. I like my Jeep, though, and have no plans on ever going back.