<p>The best way to look upon an essay is to consider it as reinforcing & harmonizing with all the other aspects of an application. If it is at least as good (in tone, in credibility, in quality, in personal authorship) as the statements in the application and any attachments, then it will not be a negative. In these days of multiple elements to an application, rarely does any one element overshadow everything else. But it is equally true that the competitive field makes it important that there be no 'excuse' to turn away an otherwise highly qualified candidate. It is not likely that the essay in itself would be the disqualifier, but it could be a tip, and where a field is crowded, tips are important, that's all.</p>
<p>This is no different than job-hunting is for adults, in crowded areas which are filled with overqualified, "overeducated" job applicants. In those cases, forgetting to re-check one's resume, being a little late to the interview, not being as prepared as one could be for the interview, etc. -- even if one is superbly qualified & with a stunning resume -- little things like that can tend to color results.</p>
<p>It's not necessary to dwell on the essay disproportionately, but neither is it a good idea to be casual about it or just blow it off because one official said it's "not that important." You don't want to take any chances, that's all. Look on it this way: the essay is the most subjective aspect of your application, not just in its production but in its reception. It is not likely that you will turn someone off as long as you don't offend or confuse. "Offend" could be opinionated about an already controversial topic (doubly opinionated), or could be an arrogant or unrealistic tone about oneself. "Confuse" could be, Doesn't sound like the same person who wrote the application (A different set of interests, different personality, different age), or that the applicant himself sounds confused about what he wants to say in the essay.</p>
<p>An essay is often just neutral to the person reading it, neither a positive nor a negative: not adding anything different to what's on the application. That's fine, because, again, it's not a turn-off.</p>
<p>Even where an essay is beautifully done & harmonious with the application, it may reveal the student to be unfortunately beautifully similar to another lovely & appealing candidate that the committee is looking at in the final round. That's just the un-luck of the draw, & there's nothing one can do to outguess how similar you might be to someone else. There are lots of decisions like this that can go "either way."</p>