Quest Hunter may lose to certain decks but it is still a brain-dead idiot deck that should not exist. When it works, you simply die to spells on turn 7. Little to nothing you do matters. There is no interaction with your opponent.
I decided to join the dark side and craft the Hunter legendaries for the quest deck. I found out very quickly that is is NOT a brain-dead idiot deck. I lost most of my first games until I figured out how to play it.
You have to mulligan hard for Drek'Thar and/or Tavish. Drek'Thar is a huge swing to play on turn 4, but you have to have him on Turn 4.
Tavish's hero power will not go to zero if you complete the second stage of the quest before playing him. Your best option against Control Warrior is to have a zero-mana Summon Pet hero power.
It's NOT an aggro deck, because you have to use spells to control the board in the beginning. Aggro decks just go face. You have to manage card resources carefully. If you use all your resources to destroy a Mech Mage's board (for instance), you might not have enough to kill her face. And you must destroy the Mech Mage's board.
I was shocked at how difficult it was to play after having been run over by so many Quest Hunters.