I don't know. I've got all the characters, and like very few changes. The worst part of the necro is that the enemy AI completely ignores your army and instead comes right for you. Boss fights are generally 10 minutes running around in a circle. It is pretty lame waiting for your minions to stab them in the back until the die.
Dunno, I really didn't experience that with necro. I didn't even consider using a health potion until level 10 or so, while I had needed it almost right away with all the other classes. Honestly it felt much stronger than the other classes to me. Not just because of its survivability, either: I almost never received a resource warning once I had access to corpse explosion, and I would frequently wipe out entire packs, including elites, before they could do any damage to me.On the other hand, my druid was constantly out of spirit and of health potions, and would die very often. Granted, not having access to the spirit animals means the class was at a strong disadvantage. But even in the early levels where the "unique class mechanics" don't play a role yet, the delta between druid and necro felt way too substantial.