Finished the game last night. I decided to use a stealthy and non-lethal approach and managed to finish the game with low chaos, getting by with only two deaths in the first mission (not sure which two people managed to die - either they were the assassins at the very start of the game, or two unlucky bastards I stuffed in a closed garbage container before setting off the explosives on the door right next to it).
The story is pretty simple, but nicely done. The plot twist in the last third was predictable - especially if you like to explore, read through journals, use the Hearth to hear secrets and listen to the audio logs - but it was well done nonetheless. As for the ending I got, I think it was one of the better video game endings in recent years - it was just the right length, covered every important plot point, left just enough room for interpretation and overall rounded this one whole pretty nicely. I've checked out the remaining two endings on youtube and I can say the same for them - the story is always rounded pretty nicely and I think it's very refreshing and a step in the right direction, especially after a ton of endings with deliberate and sometimes cheap cliffhangers. Developers need to (re)learn that they can make a sequel of a game, if they want, even without resorting to crap like that.
So, overall I'm left with a very positive impression and would recommend this game to anyone who enjoys genre hybrids like Deus Ex, Dark Messiah and the like.