I had a Jeep Wrangler before the Xterra with same type of 4x4 transfercase. An Fulltime option like was described in the Liberty would have been nice due to such a short wheel base. In 2WD, if it was the tiny bit slippery and cornering, it would do a 360 in no time with the slightest touch of the gas. I would have spent all winter in FullTime if it would have had that option.

In the X, with the longer wheelbase, the ass doesn't want to get in the front like the Wrangler unless I give it too much gas on purpose.

Personnaly, I miss not being to do shift-on-the-fly at any legal speed instead of shifting to 4WD and back to 2WD when I think I may need 4WD later.