I'm not convinced Ezekiel is benevolent.
I really hope he is, it would be sad if Castiel is the only decent Angel, of course the Winchesters can't meet too many because having an army of angel allies would make their job too easy but I want to see at least one, Ezekiel is weak so the writers have an excuse for him not using his powers to help all the time.
They could always make him a morally-grey character. He could be stealing Sam's body with the intent of doing good for (other) humans.
Castiel is also a bit morally-grey. He took the body of a guy who was married with a kid, and it's not as if his other actions have always been good.