Unrelated, my friends and I are in a spat regarding how evil mashed potatoes are and do they mean us harm. I've sent them a screenshot of this saying I have at least one ally against the potatoes. So if anyone asks, be cool!
Right, it has more inputs that I find attractive. Especially with Steam Input being a thing, I typically use trackpads as a virtual menu for some games (MMOs typically), with the sticks being the normal move/camera. Then the extra two buttons on the back, helps to bind extra commands to them or tie them to a mode shift.
A Steam Controller 2 with all the inputs of the deck would be a day 1 buy.