IMO the only truly great game Ubisoft has made in the last decade is Beyond Good & Evil which was tragically underrated.
Still, for the 4 hours or so that I played the rental of AC I had fun with it. It certainly had it's problems and wouldn't be breaking into the 9s for me score wise but I didn't encounter any major bugs and the movement/climbing was so awesome that the game was worth renting at least just for the experience of leaping around town.