SLater and Stewart are both better gamebreakers than hunt, hunt is more reliable and tougher but thats as far as it goes, he simply hasn't got the same speed, acceleration, footwork, and try scoring ability as slater or stewart. Hunt is a good ball player but his running game is average, he lacks the speed to be a devastating ball carrier
That's rather true (although Hunt's running game certainly isn't average - he's just being compared to two of the best in the business).
Slater and Stewart are more explosive and dangerous. In a game where their team is dominant they will be better, they are players who will take a good win and turn into a great win. That's why they will generally be better for Australia than what Hunt would be.
But I'd certainly take Hunt for Origin. In a very tight, aggresive match where the smallest mistakes are punished severely, Hunt comes into his own. He is very safe, he gets his team onto the front foot when he takes a kick, extremely good under the bomb, plus is also a great organiser and talker. Most people don't realise it, but he is very vocal behind the defensive line, and when the team is struggling and a player makes a mistake Hunt is normally the first one there to pat him on the back and help rebuild his confidence.
If either NZ or England actually came out and followed a great gameplan, aggresively targeting the Aussies and turned it into a real tussle, then I'd prefer Hunt out there. But until that happens, Slater and Stewart are obviously on top.