I'm curious as to how you got 50 hours out of this game without completing it. I think I exhausted two-thirds of the content in the game, and completed the main story, in about 30 hours.
I like the game a lot. At the time I think I would have given it a 9 out of 10. Now, in hindsight, I think it's probably an eight. I'd say a very good game, that falls noticeably short of great.
If you try to finish everything the game takes a long time, and it doe shave this Ubisfot feel to it of being overwhelmed with content which is rather annoying.
I'd give it an 8.5, great game great concepts, lacks some organisation and polish.