I have a nitpick with the new shooting system, there's barely no recoil, MGS4 was very good at that, you needed to adjust the aim to compensate for the recoil.
I want to see the 1st person perspective, it adds more depth to the gameplay.
I always loved proning and rolling around to get nice shots on MGS4.
The thing with gameplay is you just don't know how good it is till you actually play it.
I recall a game, where the gameplay looked gorgeous. When I got my hands on it, it had terrible handling and very slow responses.
I notice these things especially with shooters. And it takes you literally seconds to decide wether it handles crappy or golden