Put my first 4 hours or so on it on the PS3 last night... Overall impression was relatively positive.
The maps will take some getting used to, but that's the same as any other COD, and it was the same for everyone last night I'm sure.
Don't mind the pick-10 system, though it does feel quite a bit more restricted than previous create-a-class systems in that I was always finding there were more things I wanted... I actually kinda like that though, have to sacrifice some things for the stuff you really want! For example, I just gave up on having a secondary, as I rarely use it anyway, which meant I could have an extra perk, which was nice. Wouldn't have minded a launcher to take down all those UAVs though...
Like the fact that it has developed on MW3s pointstreaks even more, I love the idea of rewarding players for team based play. Domination is by far my favourite game mode, and I'm always on flags, so it's nice to now get some recognition of that! Another small change that I really liked is the fact that the B flag in dom now pulses when it's being captured by the enemy at the start of the game, so you know whether anybody is actually on there or not! I know the other flags have done that when you actually own them, but nice to get it with neutral flags too.
The scorestreaks themselves were a bit meh, nothing really super new, but nice all the same, something different. Guns were about the same; meh. Will take a little while to work out my favourite class, especially considering one has to reach level 55 to unlock ghost... Which is a good thing I guess, just means I should run CUAV more often!
As for what I didn't like... It just seemed quite slow. Playing on my normal sensitivity, normal controls etc, it seemed a lot slower to turn than in BO1. Simple fix by just upping the sensitivity a bit, but was just a little weird to start out with.
Overall impression was good though, nice to see them doing some different things and trying to innovate a little! The last two titles in the COD franchise have attempted to change some little things while leaving the basic gameplay intact, which is nice to see. Now just to get to level 55...