Number one, I would cut off all the upcs from the boxes just in case we ever do get another promotion that doesn't specify which upcs we can use.
Two, I am now a big fan of keeping the diorama pack ins that used to come with the vehicles and battlepacks as they can be awesome and quick display sets in either shelves or cabinets.
As far as the boxes I have dumped quite a few myself lately. I always have a battle with space and space won this round. I don't ever see the war going away though as long as I collect.
I am also a momc collector so I am sure a few folks here are probably trying to rehinge their jaws after my response.