I've already beaten it. I liked it a lot better than Tribunal. I will note, however, that my level 27 character got to the end of the main quest without any hitch, only to find that she had no chance in hell of surviving the boss fight. Actually, something similar happened in Tribunal, IIRC.

I recommend stocking up on constant effect Restore Health before traveling to Fort Frostmoth. Several of your opponents have it, and you'd be at a great disadvantage without it.