I'm like halfway through and I'm honestly confused about all the negativity surrounding this game. I think it's the best one so far. It's like they actually listened to my issues with the AC2 trilogy and implemented the fixes I would have suggested.
Traversal simplified down to one button? Check.
Combat was completely revamped, taking heavy inspiration from Batman, and is therefore the first combat system in the series that isn't utter dogshit? Check.
Chill out with the rooftop guards, because there doesn't need to be one on every other damn roof? Check.
Plus I honestly find tree climbing far more fun than building climbing. Just jumping tree to tree through the frontier is a ton of fun.
And it's probably just because I'm American, but I find this setting and time period where I actually have some vague understanding of what's going on far more interesting than any of the previous games.
Just wait until you finish the game and then come back with your impressions.