The habitat of the big truck-based SUV has been decimated in most regions of the U.S., not just by a downsized economy but also by downsized housing developments, downsized parking spaces and garages. The big SUV has its assets, particularly when hauling the family and the trailered toys to the lake, marina, mountain, desert, horse shows or a night out. Including today’s tester, the Infiniti QX80, there aren’t many big SUVs remaining in this segment.