Each of the smaller trays fits a (non double sleeved) deck easily, and the larger trays I use for Planechase/Archenemy cards with die bricks, and the other has a notepad and a few pens. It's pretty big but it's also really hilarious.
The compartments come out easily and go back in easily so you can take each 'compartment' out when dealing with that deck. When it closes it locks and nothing gets shuffled inbetween compartments.
My friends laughed but honestly this has done good for me, other than it being fairly large.
eyyy! I put the decks in sideways with commander on top.