Aaaa little, I think- he wouldn't have that strong self-created pressure that he has to be able to fight for and protect his team that he has as a knight- he'd be more accepting of the one needing to be taken care of because he'd have that thought of the team being there for him. I think though he would be a lot more frivolous and playful than he already is without the responsibilities of a knight so that... may not have been a good thing for him in the long run. This is just speculation though, since which team he was on would have had an effect too.

What are Itachi's goals in Aather?