I have a mentor at work who is an HBS graduate. I had a conversation with him before I went to campus and the main takeaway was that everyone has an idea of what HBS "should" be like, but when you get there you begin to realize that there really is not one "HBS type" it is a diverse group of people from different backgrounds all learning from each other. SO I tried to keep this in mind when I went to campus and I cannot really begin to describe to you how true this was. When I got to Dillon with all of the other visiting students I will say I felt completely out of place...first I was the only female there..and I definitely felt like the other visitors were of a certain "type" of person (Disclaimer: I am sure that if I got to know them well they are all obviously unique individuals with different backgrounds so I am just pointing out my first impression here based on my limited interaction. I also kinda got the feeling that some of them were just trying to play the "HBS type" part) However, the feeling in the classroom was the exact opposite. I no longer felt like I didn't belong and that's precisely because of the diversity of opinions in the classroom that HBS works so hard to cultivate. This was definitely my biggest take away from my visit, and gave me some much needed perspective about how to tell my unique story that portrays who I am not who I think HBS wants me to be. And for that reason, I think if you can visit campus before applying you absolutely should and do so expecting to observe the diversity of the student body not just the star struck "HBS type". It will 100% help you write a better application. (If you're curious the class I sat in on was The Entrepreneurial Manager also known as TEM, the case was Crossfit)
Feel free to ask me any questions! I will try my best to answer