Once you get the hang of the first few bosses they're pretty easy - the last boss is sort of a PITA but not too bad after you get used to him - just tedious. IMO the most painful part of the instance is the trash near the 3rd boss through the last boss - some mobs are immune to fire, some immune to nature, and some cast an aoe that can kill your whole team in a few seconds - its really bad, i have yet to complete the instance without wiping on trash at least once.