I play the warrior class and i am level 11 now. Like in the post before the difficulty wents up too fast, so that i have to farm health potions in the lower levels. I don't know if this is intended but its kind of tiring.
In addition to that i think that counterattack doesn't work as it should. At the maxed out level there is no instant counterattack (don't know if it was there before). When i block an attack the next damage i deal (after 1-2sec) is my autoattack which is only named as an counterattack. So there is no real additional damage next to my autoattack which makes the whole shield mastery path quite useless.