I agree they missed some factors and could improve(examples are battle backgrounds and all the typical complaints), but overall it was enjoyable and lived up to as much expectation as just about every other Pokémon game.
I think the thing that annoys me most is the Y-COMM and how you cannot remove it from the screen, as petty as I sound, a tiny box in the bottom left corner is enough to kinda kill the enjoyment of looking at the scenery, that any person with sight can agree is gorgeous.
Many of the new Pokémon are unique(Applin being a minor disappointment, it's literally just an apple) and I feel, despite the controversy, that the game was fairly well done overall.
Personally, I understand some of the complaints but I feel most people who hate it, haven't even tried to give it a chance and are just salty because they couldn't move their Abra or Chansey over to the game.
It's a pretty decent game and I look forward to the next game, hopefully one that will have looked both at the positives and negatives of this one, even if there will always be nitpickers who hate change.