I feel like they have done a good job with this CoD for where the game is at in it's life cycle.
They are working with a really old engine and they are trying to freshen a series that is getting stale.
In my opinion, they did a great job with what they had to work with. The Pick 10 system is nice and makes class choice fun. I enjoy score streaks as opposed to kill streaks. The graphics look good and for me, the gameplay is smooth. I don't have that many WTH moments. Just good gameplay 90% of the time. I like the weapon choices and I enjoy almost all of the maps.
Sure, there are some things in the game I really dislike (*cough* target finders *cough*), but that can be said about any CoD. Nothing is every perfect.
I really enjoy the multiplayer as well as the single player. I'm not a huge Zombies fan, but I have definitely had fun in short spurts with the Zombies.
It might not be my all time favorite CoD just yet, but it is close to the top.