Hah, I experienced the same thing.
Yeah, the possibilities in this game are really impressive. And the level design is done in a way to compliment that, which is awesome.
I am seriously impressed. Quite surprised actually. Human Revolution promised true choice within gameplay, but really it was all an illusion. I mean, critical decisions within the game such as killing someone was made for you in a cut-scene and everything ultimately lead to four outcomes with a "pick a button" scenario. This game is what Human Revolution should have been. I was so looking forward to Assassin's Creed 3, but it seems that this is my game of the year if not generation. If a game comes out better than this, then I will be so happy that there is one.
EDIT: Also, the duel in freeze time was just awesomely epic!