Same problems, Same game!
The A.I. is still terrible. You'll be shooting at an enemy only to have your allies pop in front of your gun and causing you to restart from the checkpoint. The A.I. still doesn't react properly with enemies in the area. They'll run past enemies saying the area is clear only to find 1 or 2 are still in the area. They also don't shoot, instead cover waiting for you to clear out the area. It's not bad on lower difficulties but playing on harder difficulties, it's down right frustrating.
I've come to accept that I'm (aka the player) is the only person capably of winning World War 3 since "I'm" the only one that can plant C4, clear rooms, kill enemies, drive vehicles, mount machine guns, rescue the hostage, etc etc. The game becomes pretty old fast when you're forced to do EVERYTHING in the game. It wouldn't be very exciting if you didn't do those things at all but some variety would be a welcome addition so "I'm" not always the bullet sponge while my allies cower in the corner.
COD is clearly focused on MP first and SP last. It's sad because the SP could be so good in COD but it feel like it's left for last. The MP maps and design is made first than the SP is built around that with some cheap explosions and non-sense storyline.
The game still runs very smooth and it's nice not having to empty half a clip into an enemy to kill them. However I'm giving this a low score because there aren't any improvements. I can forgive them sticking with the same engine but having the same issues and not addressing them is plain lazy.
If you buy COD for the MP, than this review won't mean much too you. If you buy it for the SP, be prepared for the same weak story, big explosions, expandable characters and landmarks blowing up.