We've got some that are like the Oztrail ones. I think they're made by Coleman but I can't find them under that brand when I search atm.
As they are, if you want to use them as double bunks, yes, they're a PITA but as singles, as Westvic pointed out, you can just rotate the leg joiners up flat in the bed frame and leave them assembled.
I'm planning to modify mine (with the help of a fitter and turner mate) so that the uprights between the two bed frames sleeve on the outside of joiners in both the top and the bottom frame, instead of being one solid piece that both frames must be assembled around. This way I can do the same thing (rotate the leg joiners) with both bed frames and still be able to use them easily as bunks.
Then I'll just drill and 'R' clip them top and bottom so if the kids muck around they can't pop the frame of the upright.
Might have to take photos of the mod for all the others who are pulling their hair out with this style of bunk.
Cheers!
Jono.