Regarding O'Neill I don't think anyone can deny that while he was with us, we had success. The problem with the guy is that he builds a team for himself, he has no long term outlook and it's no coincidence that teams struggle after he leaves them nor because he was THAT good.
He has his buddies in the media who make it seem otherwise and this will always make him favourite for every manager job and highly regarded in the country.
Excellent motivator and coach, but lacking in other areas of management and as many people say he's stuck in Cloughie era.