Yeah the F150s were not made for heavy hauling but that didn't stop many from trying. Even with overloads, the 40 PSI tires would sway like crazy with any real amount of weight...mind you we were always running used rubber on ours, so that didn't help.
The F250 was a different animal empty or loaded. Apparently my truck requires 2500lbs just to level it. No overloads, no bags, just a stock 4+1 leaf stack. Empty? Not exactly smooth, but almost no body roll made it surprisingly tossable in the corners. Who knew?