My buddy had one of those a few years ago and it always rode like, well, one of these:
You can see the resemblence...
Since you're sitting out over the front wheels, you'll get an accentuated effect from every bump. My F250 has a GVW of 8800# and I can run the E rated tires at 40PSI in the rear and 50 PSI up front without it feeling too mushy.