In my own personal work, I've found that my response to criticism is often very similar to what Madeleine L'Engle describes, I believe it's in Circle of Quiet. Very often the criticism that I have the most violent emotional response to and defend most passionately to the critiquer is the criticism that, upon a few days reflection, most represents what needs to be changed in the story. The criticism that rolls off of my back, I usually do not end up changing because I'm already looking at the information objectively and have made my decision. It isn't always true, but for those friends who have been brave enough to give me a no-holds-barred opinion, they've often been those who have helped make my stories better.

It's a good essay. I'm hoping that I've grown enough that I'm able to objectively take well-thought out criticism or beta-ing, and in fact sometimes I crave more precise beta-ing, actual character and story thoughts as opposed to only aesthetics - grammar, etc. I don't think it's every actually easy to take criticism of a work though!