While I don't have any direct experience, thinking logically and critically about this, I would have to conclude that the beds will hold up just fine, and here's why:
Any rough handling of the camper that would damage the bed, would also damage the camper. Since you don't want to damage the camper, odds are you will be careful to the point where you won't damage the bed.
The Chevy anti-aluminum advertisements show loaded metal tool boxes being dropped on their corners, or large chunks of crushed stone being dumped by a loader from several feet. You won't be doing either of those things with your camper, so I would not have a moment's worry about the aluminum beds.