So, If I may ask....you mention that you took your Jeep....and thought the X would roll over....
Would you take your X? Would you suggest me taking my X? Is that a trail that 35's and front/rear lockers is a base necessity?
Great video series on the Rubicon here:
Pay close attention to what the young lady says just after she flops her Jeep at 5:50-ish.
"I had both of my locker on and couldn't steer..."
I think you could run The Rubicon in your Xterra...with an experienced crew prepared for long days of patience and recoveries.
The Rubicon is a no bail style of trail, point to point.