While I believe I had a good GPA, GMAT and work experiences, he helped me build a narrative. He seemed to know exactly what HBS wanted and what type of applicants they accept. His method is extremely blunt which is great; this helps you understand what the admission officer would be thinking when he/she reads your essay. His mock interview was brilliant as well and after doing it, the actual one was a breeze. He kept pressing me on certain points that were weak in my application. Essentially I feel what he does is helps you create a great story and then weed out any unnecessary fluff.
But if you are applying to the best business schools in the world, you should have the ability to work with anyone, especially someone with Sandys insights. If you are thinking of spending $2000+ on a consultant, spend it on Sandy without a doubt.