An Xterra has a steel bumper, too. It's just covered in plastic. (which is almost ripped off mine)

Well that steel bumper won't help when you (in the TJ) have the incredibly weak Dana 30/35 combo. A Rubicon with a lift and upgraded steering is nice, but not just any TJ.

If you spend some time looking around this forum, you will see plenty of pictures of Xterras completing hard-core trails.

If you think Nissans are so inferior offroad I welcome you to attempt obstacles like Cleveland Rock (Holy Cross), Tip-Over challenge (Hell's Revenge), White Knuckle Hill (Pritchett Canyon). All of the listed obstacles have one thing in common. They are extremely difficult for SWB vehicles to conquer. All have been conquered by Nissans.

Like I said, Xterras and Jeeps alike are driven mostly by grocery getters and dirt road drivers. Just because the Xterra happens to be useful doesn't make it as outclassed as you suggest.

IMO the only Wrangler worth considering is the Rubicon Wrangler Unlimited.

Regular Heeps just break too much.