Especially considering this: http://www.giantbomb.com/dishonored/61-35850/it-wont-do-the-3-4-different-decisions-at-the-endgame/35-563037/
You didn't choose between 3 endings in the final mission which was cool but there weren't any multiple endings in that way. You only had the two unless you are a soulless dick and got the worst ending. But I think this is a case of looking at the journey not the ending. The journey affects the ending, not the final mission. But there should maybe have bin more player choice in that mission.
The game is very well done in many areas but at times feels rushed. The final mission was very unfulfilling. If there was any aspect of Deus Ex: HR that was lacking in this game then it was the conversation "battle" you could have with NPC's and convince them to do something or talk to them about their plans. The only interactions you had with characters was either killing them or putting them to sleep.
But no game is perfect and a I had a blast playing this one and it is a definite replay for me :)