I really liked Ezio's character progression - it wrapped him up nicely, especially with the Embers DVD which came with my set. One of the best characters this gen, so this game gets an extra point just for that. Additionally, after playing as Alta´r again I no longer think of him as a total tool (although the voice actor making an effor this time probably helped too).
Gamewise - it did seem more limited in scope than Brotherhood. The tower defence didn't really work for me so I locked it down as soon as I could, but the bomb crafting was a nice touch that surprised me how much I used it. The side quests did seem a bit vague compared to previous games.
Just adding honourable deaths to the MP is enough of an improvement to warrant a tick there.
Did anyone else feel that Revelations was glitchier than the other games?