I was hesitant to play Syndicate after the screw up that was Unity. I was a huge fan of the series, owning books, games and merchandise, but it slowly dissolved after each game became less and less interesting. Black Flag was the exception, but that's because it wasn't the typical Assassins Creed story. Syndicate however is a return to form, which a fantastic setting with London and two fantastic new antagonists that had life in them. They were new and fresh, which made the story enjoyable.
The problems with this game are all pretty much the same as the rest of the franchise, with clunky controls while free-running makes some tasks frustrating when your character runs in a different direction. Or the collect-a-phon of objects that appear on the map that get boring after a while. Or having to do the same style of missions over and over to “liberate” sections of the map from enemy gangs. These are all the same issues that began around AC3, and with Syndicate being the 9th game in the franchise, you would think they would have resolved these issues by now.
Overall the story is good, the characters are great, and the environments are beautiful. But if you had given up on this franchise because of how repetitive they are, Syndicates not going to fix that. But if you are a fan of the franchise, Syndicate is a great addition on par with Black Flag.