This is a 4runner forum so most will tell you to get the 4runner.
I will not. I would get the Xterra. I had a Frontier and I liked it leaps and bounds over our 2011 4runner.
Problems with 4runner:
-Storage
-Sway
-Rear Sag when Towing
-AC needs to blast to get cool. (living in AZ)
-No Driver...