My opinion on halo 4 is generally... Epic.
The gameplay footage is awesome (especially campaign) en the multiplayer looks indeed fast paced as 343i had intended. altough there have been a lot of changes I still like it (change is sometimes good you know)
The only thing that bothers me is promethean vision. They said it wouldnt be over powered... But an ability which lets you see an area of 40m (thats my guess) for 5 seconds seems a little bit OP te me.
But besides that I really like the gun sounds, rag dolls, assasinations, etc.