Amazing but...
Graphics- Awesome, hardly a flaw to be found. Framerate rarely get's choppy, and when it does it usually has to do with a bit of lag while playing co-op. Best character design I have seen to date, except maybe MGS4.
Gameplay- Love it, makes you frantic when you can't just run and gun. Aiming system is easy. Mercenaries is easier than the fourth for sure.
Sound Design- Well as far as I can tell superb. Being that I don't play with anything other than standard sound.
The other little problem I have with it is the ending. Not really what I was expecting. But it does leave a lot of questioning as to what they will do with the series in the future.