I have never reviewed a mod before, but the quality of this one, the effort that went into it, means I have no choice. It's superb. It does a brilliant job of hiding AC's visual flaws, much better than any other mod I've ever seen, it's scenic(I love the turquoise sea shades), it even has the sounds of exotic birds when you idle by trees. It's just mindboggling to me that this is the creation of one person(I think?).
The thought of what modders like this could achieve with a graphics engine that didn't look as bad as AC's is tantalising - hopefully AC2 will sort that, and modders like this will be able to do even more amazing things. Anyway, just get it, it's fantastic. It's the best free-roam mod I've played so far.