I agree with you on the main game. I think it's well done and only has some minor glitches (from my experience, played it through twice) that didn't annoy me too much. It's highly ambitious in size and scope. However, I think the DLC is trash. It's not very compelling, there aren't really too many features to keep me interested (a new outfit and animal features) and way overpriced for the length. I feel I got ripped off getting the season pass. For me, the Red Dead Redemption Undead NIghtmare was the pinnacle of DLC for me. It stayed true to the game while giving it completely new spin. I don't really get that fresh, new feel from the King Washington DLC.
For me it felt like the game was mostly side missions, go here and come back missions. I finished the game a couple months ago, I can't remember any main missions other than I had to chase people or sneak/hide.
Connor as a main character was the worst too. I couldn't tell if he was forgetful, a hypocrite, or someone who had split personalities.
Along with the story itself in AC3, awful. The entire series was assassins vs templars and that wasn't even the case in AC3. Also can't forget the horrific FU ending.
I do agree about the cities. I'm surprised it only had New York and Boston and not Philadelphia or Charleston, etc. Add some more settings/flavor that doesn't make it feel like New York and Boston are the exact same city. If you removed the soldiers, i.e. orange vs blue coats, I wouldn't know the difference.