dundundun
I had a family member read my app for typos etc but that's it. I'm a pretty militant believer that 3rd party advice on how to present yourself is counterproductive. We're not professional writers and that is not the standard by which we are being judged. We are aspiring business leaders and we are being judged by the content of our ideas, not the quality of our writing. So we should focus on our individual business identity and presenting that clearly and succinctly. You don't need an editor to do that. In fact the editor, in editing your writing, will try to edit your identity, and that will only hurt you.
While this may work for you, I feel this may be extremely bad advice for many people. We are being judged on how well we present our ideas, as well as the content. Not everyone is a superb writer, and failing to have someone make sure that an essay flows and represents the author the correct way can be detrimental.
Just like in an interviewer, where your demeanor, communication skills, and professionalism are just as important as what you say, the essays are more than just content. It is not only about "what" you say, but "how" you say it.
That being said, I think many people -are- capable of succeeding without having someone proofread, edit, or reword their essays. Many people, who do not write on a regular basis, need more guidance.