I watched that video also, and was less than impressed with the Toyota frame in the static load tests. However, the part of the video where they run the three trucks across the bumps and watch the rear of the truck is, in my opinion, obviously slanted to make Ford look good. Every suspension has a resonance, and any vehicle driven over those bumps at the speed that would get the suspension into resonance, would look bad.
Granted, the 3/4 ton truck has stiffer suspension, bigger brakes, and is overall heavier duty than a 1/2 ton, but in my personal situation, I felt the 3/4 ton was not needed for the load of our 23'. Additionally, I felt the 3/4 ton was a liabilty in ride quality and fuel mileage when not towing the AS which is about 85% of the time.
I recently bought a 1/2 ton, extended cab GMC pickup equipped with the towing package, and the 5.3 liter gasoline V8 and could not be happier. The truck pulls our AS without any problems.
I did drive a Ford truck of simular specs (1/2 ton, extended cab, 5.4 engine with towing package). I thought it did not have any where close to the power of the GMC, was not rated to get as good of fuel mileage, did not ride as good, and had the most uncomfortable seat I had ever sat in. I have a bad back and by the time I had driven it a couple of blocks, I was in pain.
I did get under the GMC and look at the frame, and although I certainly have no way of testing it, it is built very simular to the Ford frame....totally boxed and about one foot tall in the center section.