Simply put, Sandy knows what HBS wants

He knows how the admissions department shapes each year’s class and how an applicant can accentuate his or her talents, experiences, and passions to become an attractive prospective member of the class in the eyes of adcoms. 

As many clients have said it before, Sandy is assertive. Unless you feel very strongly about a certain point, I suggest you follow his advice. Sandy will also quickly cut through the BS by telling you when he thinks your output is garbage. You may even find his bold comments humorous, making the entire application process less stressful, as I did. His response time is consistently very good (usually under 12 hours, max 24).