I used essayedge before. They provided a pretty insightful response about what worked in my essay and what changes I could do to strengthen. I don't think it should be used on the pretext that they will write a essay for you although I believe they do provide that service for $$$ b/c it won't ring true. I used essayedge after letting everyone I knew read it as a final polishing step. Most important thing is that your essay should be genuine. I know its hard to do but if you speak from the heart, then it'll stand out and adcoms will remember you.