Longtime lurker and first poster here. Invited to interview last week -- international exposure in manufacturing (corporate finance) with essay focused around a significant professional experience with details of my personal and professional "story" sprinkled in, decent GMAT, unremarkable GPA, no extracurriculars. The essay was my determining factor.
[ Tip for international applicants: family and friends from the USA (where I was born and grew up) read my essay and commented that some of my English was askew - phrasings and various bits have worked their way into my vocabulary over my nearly 3 years abroad in a developing country working for a British firm. This can stand out and potentially be a positive when the Adcoms read it, but can also sometimes be confusing if they are not aware of the differences in the first place. I definitely recommend having others read your essay for this very reason, among others. FYI, an example was "take a decision" (England and foreign countries) versus "make a decision" (America).
Good (although dated) article on the subject:
https://www.nytimes.com/1989/04/16/magaz ... ision.html ]
Overall strategy: I am only applying to two schools so that I don't spread myself too thin and I focused on making sure the completed applications as a whole projected my story and the perspective I could add to the schools. I took the GMAT early and only once (in January 2014) to get it out of the way. I read the essay prompts when they came out in early June and let them sink in for a month or more before writing anything. Liaised closely with my recommenders making sure they understood the "why?" and crossed my fingers.
Best of luck to all who gave it their best.