The slyphs, without a doubt. Almost every single one of them is ranged, and it's really hard on a melee player there considering how often you have to pull a mob back to get them out of the other's aggro range, only to aggro something else. Plus unless you're keeping track of names, it's hard to tell which ones ARE melee. I'll take every other level 40+ zone in the game over the Slyphlands, since at least then you can see their weapons and know what you're about to face.