The only thing I really dislike with the new devour...
Is the fact that it makes the junglers play like they have blinders on half the time. I understand that there's more to jungling than ganking, believe me I play it quite a bit, but most of these players just go in the jungle and exclusively farm, quite often at the expense of their team. Cover the lane because I have to recall? Naaa. Push tower after I/we killed someone? Naaa. And the list goes on. The jungler quite often sets the tempo for the game, and sitting in your jungle so you can get that "sated" while you're losing the map makes me dislike the item.
If you're going to play it, please try and see where you can help. 30 stacks is a long way to wait for you to appear from your jungle. And please don't pick a devour jungler if your team needs some sort of CC/Tank. While you might think you can carry the game, you're just making it much more difficult by picking a bad comp. Maybe I'm off base here, but these are the big things I've noticed, and some of my friends have noticed ever since it's been introduced.