I think I speak for my whole guild and most of the top players when I say that tank runes, and to a lesser extent unbreakable heart, have ruined PvP. They slow down the matches a lot and invalidates the whole tanke class.
Having to check the rune setup on every defender is a chore.
Suggested solution: replace the taunt function with a significant defence bonus, for ex 20% damage reduction
Make Reptiles Great Again!