I'm maybe halfway through and my main thought is "oh my god this is gorgeous". I love architecture and good level visual design and UC3 is basically constant bliss for my eyes. Every level I think "this can't look cooler" and then it does, just utterly bonkers. And the characters look so amazing, I really can't believe how good *everything* looks. Easily one of the best looking games I've ever played, likely helped by the fact that ND seems to have read my mind about locales and environments I love the look of and made a game about nothing else lol.
Also on the plus side - I love the characters and the story so much. I'm surprised how often the little touches crack me up, Drake's tiniest gestures sometimes have me laughing out loud as does the interplay between the actors. Set pieces, cinematics, propulsive storytelling... insane marks all around, just as I'd expect from ND.
Minuses... the controls have never been the strong suit of the series and while in U1 and 2 they were certainly "good enough" in 2011 this isn't quite the case anymore. U3 really suffers from having a melee system in a shooting game that comes out a few weeks after Arkham City showed off probably the best melee combat any action/adventure game has ever had that I can think of. It's not a total apples-to-apples comparison because Batman is not a shooter at it's core but U3 also suffers from still having some janky controls surfacing during platforming. It's a shame, but at least it gives ND something to shoot for in U4 - a totally revamped control scheme maybe. While I'm wandering around the levels with my mouth wide open stunned at the quality of the surroundings and laughing at how much fun I'm having listening to the characters interact ("she's still wearing it!") only to have Nate fail to jump on a ladder twice in a row... it's unfortunate. ;P I guess it's a function of the player animations not quite being up to par with the rest of the game too.
Anyway, this is still one of my favourite games of the year, it's just a pity that a few elements don't match the "holy shit so good" factor that much of it does. Oh and as far as the shooting goes I think I know what ppl are talking about with the weird 'dead zone' issue but it's not a big problem for me, maybe because I'm playing on hard.