Just started playing this, graphics are really beautiful though FPS seems to be a bit unstable, as it often moves between silky smooth and well.. not so smooth pretty polar opposites, but still playable. I'm aware the console versions are locked to 30fps, might actually not have been a bad option to have on the PC versions too considering the massively varying fps you can get.
Was really pleasantly surprised when I heard the main characters voice... "wait is that a Welsh accent!?" and then a little further... yep that's a Welsh accent.. A Welsh leading character with a properly done accent was a big surprise. Though he does go from a very posh Welsh (that would probably sound English to anyone not from the UK) to a pretty strong townish Swansea accent a lot I think they did a great job with it!
This is the first Assasins Creed game I've properly played, I have AC2 but never really touched it. Controls seem to work real nice and the combat is fluid (though seems a bit almost like a well disguised series of quicktime events) and the sailing of the boat is pretty nice. Not very far through it (just beat the intro part) but I think this is a game I will really enjoy.
Only negative would be the fps optimisation, I'm playing with a PS3 controller... works great!