I knew I'd hate it before it even came out so I won't waste my money or time with it. After MW3 I learned my lesson that IW couldn't make a decent game without the talent that left them after MW2. And I'm sure you'll rage enough for both of us when you get quick scoped 1 off a kill streak by some bender in his little helicopter that he worked so hard to get by going 10/35.
Being shot from behind wouldn't be a major issue anyway since you can hear footsteps in this game (including dead silence), the only game with that problem is Black Ops 2 since people can sprint at you over broken glass while wearing clogs and you still wouldn't hear them.