Pre-nerf Mythoclast could down a player in PvP in 4 rapid shots, 3 to head. Now, personally, it is reasonable. I got one post-nerf and enjoy using it and it feels like the other Exotics do. I have only heard now insane the Fatebringer is and have to wonder now long before they nerf that too. I agree though, Exotics should be above Legendary. But there should never been a single go to Exotic that is defined as "the best". It brings around the same problems of auto rifles/shotguns in the Crucible. There should never be a single mega weapon that by default is better than any other.