(Core Set perspective) A really sweet card. Getting an armor piece back every round (while you're setting up in Tony form) means that this can act as a pseudo additional (and cheaper), Helicarrier/Avenger's Mansion (with the downside of not being as good for other players at the table).
Being able to discard armor pieces for resources (often the same piece multiple times), with the ability to grab them back later when you're ready to play them, gives you fantastic flexibility.