Oh, 40 years driving vehicles, I guess that makes you much more of expert then the rest of us who have been driving vehicles for as many years.
Tony, I know you think I am picking on you but to my mind you present things here as rock solid facts when they are simply your opinions. That is just my own opinion and it could be right, wrong or somewhere in between.
Work horses (in my opinion) take a flogging and keep going. That has been how American trucks were built, you could overload the heck out them and they would keep going. I am not claiming they were better trucks, just overbuilt and durable. But as PertosA mentioned those features made the trucks heavy gas hogs. They also tended to be rough riding.
I can't comment on the trucks you drove and I have no idea if your trucks are the same as the 2015 American Transit.
However, regarding the Transit I am driving I will not believe the bump stops on it are not active suspension components when approaching full load.
Presently I would guess the Transit is at about 50% payload limit, I have not had it long enough to finish filling it with junk.
Now look at the pictures I have included, the Transit has very little travel left with this 50% load, the bump stop is huge and the leaf spring pack very small (just two leaves each side). I would be very surprised if it is not sitting on these bump stops at full load.
Now compare that to the American truck with its small bump stop (black rubber circled in red) and its huge spring pack. Both trucks have roughly the same payload rating.
The Transit is not even close to being as rugged.