All of the missions do boil down to a few repetitive tasks: Beat someone up, evesdrop on soneone, steal something from somone, and then kill someone else.
But its a great looking game, and quite fun to play. If you want to be doing something completely different every second then this isn't the game. But if you don't mind doing the same thing slightly differently, its good.
I still think fleeing back over the rooftops to your base after you kill one of your main targets (there are 9) is one of the most exhiliarating experiences. Every guard watching you on high alert, one toe out of line and the pounce! Great.
And theres plenty of scope to just wander around the world either looking for flags (there are about 420 of them) or just find new free-running lines through the world.