I haven't faced any big priests yet while climbing, but I imagine the matchup is 40/60 for the hunter. If they Barnes on turn 4 into Yshraaj, the game is typically over. Replacing Loatheb with BGH as a tech can help with the matchup a little bit. Owl is also clutch for when they cheat out Obsidian Statue. But the goal against priest is to absolutely ignore everything and go face. Hopefully the upgraded hero power is enough to get you there.