Is it possible to generate a function where the user can easily see which cards they have in each expansion/edition, and which cards they are missing in each expansion/edition?

Since many of us are using deckbox to keep track of our collections, this would be a very nice feature to have.

It's been alot of negative talk regarding pricing of cards, now that you've lost TCG price tracking. But for me that is only half the value of deckbox, keeping track of which cards I have/don't have is even more important.

You can already see which cards you have in each expansion. As an example, here are all of the cards I own in RTR.

The second part of what you want, to see what your missing, would definitely be a good addition.

To see what you are missing, go to the Card Database, set your filter(s), and go. With the way things are, you have to scroll through, but you get your inventory, wishlist, and tradelist counts right there with every card printed in the results. Hopefully it will get fixed so we can sort on those columns again soon. That was always the primary way I identified cards I needed to add to my wishlist.