You can fit 4 Adults in an FJ fine...the door is kind of a pain, but there is room. Also, like you said...Real world mileage for the FJ is better then then BMW.
The only time I have seen an H3 off-road is Moab...April 06. So what is that...10 months after release (no idea what the actual release date was...just guessing June 05)? Does that mean that they weren't off-road before then? No. Does the fact that you haven't seen FJ's off-road mean they haven't been? No.
Besides...last I heard you thought a paved road going over a pass was a "scary trail"...so it might be hard to see other trucks off-road if you don't go off-road yourself...right?
Just sayin.