I'm on the same mission as you, Shipwreck. I rarely "rage quit" any games and AC3 has made me do just that. I tried that same mission over a dozen times. I'm probably going to have to wind up bypassing the side mission of disabling the cannons just to get on with the story. I can't stand spending 10-15 minutes every time sneaking up on every person in that fort just to have the last guy (who's guarding the map in the tent) spot me. Shipwreck, I know you said that so far the game "feels like Assassin's Creed" but I have to disagree. I think the amount of frustrating missions the game gives you so early on in the narrative is very unlike the rest of the games in the series.
I know a lot of people are feeling letdown by the Wii-U being only slightly better than the Wii but honestly I think that's going to be a trend going into the next generation of systems. I feel like I say this every console cycle but I can't see how much better graphics can get on these next gen systems. I think the next gen systems are going to be dominated more by gimmicks like the tablet controller and the Kinect than be truly powerful machines.