Ill put it to you this way.... Ive had near 10 F series trucks, some 2wd some 4wd. Ive NEVER broken a twin I beam front end.
Ive has all the bushings wear out and the ball joints go to hell.... but they stayed togather.
The big things to keep up on is the tie rods, radius arm bushings, and I beam pivot bushings. the pivot bushings cause alot of the rattles and the negative issues.
Yes, its murder when you put a plow on them, my 84 F250 wasnt too happy with that, and they handle pretty good with a good alignment and good tires. My lightning handles like a sports car.
I like the I beam front ends, sure they have there draw backs, but I havent broked one yet and thats a good thing.