It seems like this thread has not received any new reply for a while. I basically opted out from hiring a big consulting firm, and instead did my own applications with the editing services from various professional writers/companies. And here are reviews.
1. Essayedge.com - A complete waste of money. Their supposedly MBA essay experts generally don't have much experience in editing the MBA essays. They may have some WE in finance, but they are mostly just professional editors who may be good at general writing, but not specifically for the MBA admissions essays. I was so displeased with the service that I filed a complaint, not to ask for a refund, but just to let them know that they suck. I get an email response from a college student who works at their front desk, stating that she has reviewed the edited version and found it to be impressive. I mean… seriously??? A second year local college student is gonna make a decision on the quality of my MBA essays?? I even asked the kid what was the qualification for my editor. She basically ignored my question, and repeated that there was nothing wrong with the editing. If anyone is interested, I'd be willing to send you my original essay and the edited one to show how ridiculous it was.
2. Local university writing center: I happen to live by a top 10 college with a very good writing program. It was FREE! But while the editors were all talented writers (mostly graduate students), they just made my essays stylistically fancier. I felt like their writing styles buried my voice and character as a unique applicant.
3.
Gurufi.com: I've only used Brian so far. But man… he is awesome. He not only polished my writing with a style, but also made my voice more clear and easily understandable. He made any further editing or proofreading pointless. His fee was reasonable, and he was also very quick in responding to my msgs. I'd highly recommend Brian. If I end up using any other editor besides Brian, I will update this post with that info as well.
4. Essaysnark: My co-worker who is also applying for MBA used Essaysnark. They usually offer the service per school or as a four school package. He really liked their editing. I took a look at his final essay, and I was pretty impressed too.