ET hitboxes have always been inaccurate sadly. Many of the movement animations that players perform in-game distort the head hitbox specifically.
When what is left of the CyberGamer elitist complain; I do believe their main complaint is not of the accuracy of the hitboxes (because neither pro or pub are accurate) but rather it differs to what they've grown accustomed to for the past 6 years of playing this game. Unable to adapt because they've "learnt" to aim a certain counter intuitive way, they complain.
I don't have a real issue with the OZ hitboxes, but they certainly do feel "different" to what I'm used to.