The FJ cruiser is promising on the surface, but a failure in practice. In the interest of style, Toyota gave it very shallow greenhouse with very small window height and a dashboard that looms high, meaning that your sight lines are terrible. It may not matter in the wide open dunes, but generally for off roading, this sucks, not to mention that it creates claustrophobia.
Its also not as compact as a true shortwheel base 2 door, nor is it as practical and usable as a true long wheel base 4 door. the crappy rear half doors make for useless vehicle from a usability and utility point of view.
If I were buying, I would buy a Jeep Wrangler Unlimited, the new lwb, 4 door version. My second choice would be a lwb Nissan XTerra. I would not even look at the FJ Cruiser. the FJ makes a very positive impression when you look at it from the outside, but it sucks in actually use.
Check this out:
Hummer H3, Toyota FJ Cruiser 4WD, Jeep Grand Cherokee Laredo 4WD, Nissan Xterra Off-Road 4WD - Comparison Tests - Car and Driver