I normally play caster charaters.
My latest one was an ice mage (due to the fire mage abilities just not having the nessecary crowd control needed to avoid getting swamped by the mid twenties). I focussed on ice mage skills with ice rain, the shatter ability and permafost, the skill that increased cold damage and teleport for quick get away. I had tried lots of different builds but thtat seemed the most effective.
By level 35 I found normal mobs could one hit kill me and by damage output was ineffecetive. This was despite setting the dungeon level to a few levels below mine. I feels that the skills do not scale well at the high levels for mages despite sinking alot of points in them.
While I understand as we start going up higher levels rebalancing skills and different equipment is needed that isn't really practical when neither defense nor offense is higher enough.
That said its a great games and I'll probably play it some more, its just frustrating when adding 11 skill points only increases damage by 10 points and there is no feasible way to increase defense to a level high enough to protect the character. As a result I get bored because playing a caster becomes pointless and I like pure casters.