Originally Posted by Drithius 
Are things still a challenge at higher levels under Vanilla?
In short… no.
It doesn't really matter how you play either. In my game, I tried to be a "jack of all trades", and I was still a god by the time I was 2/3 finished.
I'm a completist though, so it was sort of unavoidable simply because I put so much time into the game. If you're able to ignore some of the sidequests and just concentrate on the MQ, then it's probably not as bad.
Are you playing with Tribunal installed? If so, I highly recommend
this mod.