Toyota = huge off road/overland/4x4 after market
Nissan = niche/boutique/one off after market
Having owned 6 Toyotas (Hi Lux p/u's and 4-Runners) I purchased my first Nissan Xterra in December of 2009. I test drove an FJ Cruiser, Jeep Wrangler Rubicon, 4-Runner, and two first generation (pre/and 2004) Xterras...and I bought my 2005 shortly thereafter.
Price was considerably lower, and I really liked the power of the 4.0 litre V6 compared to others, as well as the (for me) utilitarian interior and features (lots of 12V power sources, center console, rear cargo area, as well as cargo area tie down locations).
Since owning it I have done well over $15K in modifications getting it to its current state...but personally I enjoy looking like not every other vehicle on the trail. And one of the most oft heard comments is..."How'd you get that Nissan all the way out here?"
If you can afford it,
GET THE Pro4X model. You won't regret having the rear locker factory installed, the 3.36 gearing, as well as a host of upgraded interior features.
Don't buy the Xterra if mileage or commuting is an issue. They are not fuel thrifty vehicles...and once the mods begin, it only gets better.
Pick your poison, and enjoy the ride!