Thanks a lot guys for your feedback. It really helps a lot!
We fixed some of the reported issues, and we still have a bunch to fix 
We take it people are missing the deck count warnings, and Laura has implemented a red highlight for the deck counts in the cases where they're bigger than inventory counts.
We are still monitoring feedback for the Add Widget, which - I agree - could be made a bit more intuitive. Still thinking about what improvements to make there.
Also it looks like a lot of people were fans of the sortable count columns, so we will try to bring them back.
Notably some issues still open and which have high priority are bugs related to sorting collections by price / edition and deck indicators.
Bug fixes have priority right now, we'll post more about "design" type issues in the coming days (add widget, grouping of cards, trading opportunities etc)
Thanks again for all your input, we couldn't do this without you guys 