Bloody hell, I haven't even finished AC2 yet! I got to the bit where the world pretty much opened up and I rather suddenly lost interest. I mean I had fully upgraded my little town, I'm pretty sure I had every weapon (only one of which I ever used) and I just got the impression that a massive grindfest was just lurking over the horizon ready to make me really have to suffer to get more story.
I've never been big on completing all that stuff. I left much of the game unfinished and just powered through the storyline. I really couldn't care less about side missions or armor upgrades or finding lots of random feathers.