I personally think that saying its all about the player and not the character is also very wrong. Lots of people refuse to give the character credit. While i do agree that Omega is really good and that a player skillz is more important than how good a character is, you cannot pretend that its ONLY a player's skill that wins a tournament. Omega proved that he's one hell of a player but he also proved that Nightmare is one hell of a character if played well. All is not black or white.
People saying bla bla look at frame data. Frame data isn't the only deciding factor in SC V it is if you play a really mathematical game of safe attacks and block punishing game. Omega and Keev play an insane spacing and whiff punishing game. They mind fuck their opponents install fear and condition them to do want they want. Nightmare is REALLY good for this kind of gameplay.
As for tier rankings i won't say shit cause it's far too early.