You had 8 slots to choose from on the d-pad for whatever item/weapon you wanted, available in an instant even in the heat of a battle. With the mini-menu system, it abruptly pauses the game for you to tediously scroll and find what you're looking for. Also, it's alphabetized, which is arguably awful, especially since you can't change it as far as I know.
Why did they change it? or rather, why didn't they give the option to use either systems?
I've said it before, but a fusion of the two would be perfect. By tapping the d-pad you get the old Oblivion/Fallout hotkey menu. Hold it and you get the Skyrim favorites menu. They could even give each direction it's own list to help cut down on the massive clusterf*** the favorites menu can become.