I don't think there is any definite research proving one way or the other, but they seem to be more manageable as time goes by. All the South and Central American beeks are keeping them and making honey. "money"
Most of the reports I have read from them say they do not want Italian bees back. They prefer the hybrid African.
My opinion is, the European traits will increase as they move north, and the African traits will be reduced, thereby making them more docile while being able to withstand more cold.