What most irked me, is the randomness in the final battle. Not only because of the randomly spawning monsters, but also because of their random movement patterns and the inherent randomness of melee attacks.
I sometimes, if I didn't take care and even if I did at times was closed in by monsters and just at that point my two front row fighters also thought it would be a good time to miss their attacks or not do enough damage, as skills from higher skill point levels (e.g. in Swords or Maces) are, at least as far as I could see, applied randomly and not when you'd want it to (like, say, in Dungeon Master, where you chose the attack). My rogue was skilled in Missile weapons and carried the stun gun, which did damage to normal mobs, but not much. Next time I'll use a throwing weapons rogue. And even the mage was not able to dish sometimes dish out enough DPS in concert with the other to kill the monsters blocking me in.
So basically it comes down not so much to skill, but to how you can deal with all those random factors at once.