I think it would be a nice feature if we were able to select which decks we were sharing cards between and which we were not. For instance, I have several precons that I like to keep together, but the rest of my collection is more fluid. I run into problems, for instance, if I have two copies of a card and one is in a precon while the other is in my cube/general deck circulation. If I want to make sure neither are listed for trade, I have to make a separate decklist that includes two copies of that card.
If we were able to make a selection on a given decklist so as to include the deck's cards in the 'shared between decks' group, I believe that this issue could be avoided.
Otherwise, thanks, I love the site!!