I actually felt like incarnate became kind of meh close to the last bossfight, so i started using artilery plant instead, and man that thing is doing insane damage. I think that incarnate should actually be rebalanced, because it's considerably weaker than summons from other s-trees.
I think it's because other summons are balanced around not having points in summoning, which is understandable, but still a bad balancing decision overall.
But we all should keep in mind that there are source spells that may oneshot even the beefiest bosses, and they still overshadow all the power that summons provide.