Most likely rust it 1st. They look cool ,especially with the factory canvass but Ill stick with my tray.
There was a post from an old timer on exploroz who had had a 45, 2 x 75 and 79,all with a factory tub and each was made from progressively thinner metal.
The last one he had would bend in at the top when he put a heavy load in the centre
Some of the newer 1 tonners in the Japanese utes probably have bigger tubs than the 79 now and can carry almost as much in weight.
By 1 tonners I mean the Hilux,Navara Bravo/Ranger types.
Its funny how the smaller trucks are doing the jobs of the full sized 4wd now