Braindead story. Obnoxious hero. Lame combat. What could possibly be wrong?
Diablo 3 is so easy, I think I died less than 10 times the entire game. Nearly every boss fight is trivially easy. Character development is dumbed down, if you can believe it. No more stat assignment. No more shrines that have a permanent effect. No spell books. There is nothing you can do that can not be fixed by simply investing more time, returning to once cleared areas that are inexplicably refilled with creatures when you quit and continue.
There is a crafting, but the best it offers is still so random that you still need a lot of luck to get what you want. Blizzard has topped off the insult with an infernal DRM system, that can even give you LAG in your single-player game. God awful.