Although it looks good one thing that bothers me in this and in Tomb Raider is a sense of injury or fatigue.
MGS4 showed a good level of fatigue throughout the game playing as OLD Snake, it really drew you into the fact that he was weaker.
Ezio should move relativley the same but we should hear his breathe and have animations that show his age, like when jumping, he should take a few more second the hoist himself up, when rolling take a moment to compose himself, it gives the character more depth and if done right wont slow the gameplay down.
Same with Tomb Raider, Lara was holding her side in pain and moving jaggedly but when it came to jumping it was like she was an olympic class athlete without any evidence of injury, fractured bones and so forth