I find the killer feature to be the ability to pause games. Sure, I could do that on my PC, but since this whole Deck is dedicated to just running the game, and I can set it aside, do the thing I need to do (maybe on my PC) and come back and start right where I left off, it feels different, more integrated, because for a little while, the game state and the deck state are the same. It is less like the Deck is running the game and more like the Deck is the embodiment of the game.