Maybe I'm a minority here but I only have one large problem with mythos-The dificulty. I feel like some invincibility cheat on. Even  as a pyromancer enemies hardly touch. WTF.

I'm up to level 16 and while I am enjoying the game, I do have to agree that the difficulty could be cranked up a bit.
I've only died a couple of times, and that was to bosses. The bosses seem to be setup to be either dangerous to melee or ranged characters.
Not much point to grouping at this level as you absolutely bomb through the content.