The interview process, when I interviewed was fairly tough. They really wanted the candidate to meet EVERYONE. The interviews were also in-depth. I understand how it could be overwhelming for some people, but after subsequently working with everyone there I understood more that they were trying to get to know me to see how my personality and work ethic would fit, and if I liked them as well (it's a two-way street--you need to like the job too!).
If anyone has any hesitations I would say simply: push through. If it feels like the interviews are a lot, it is worth it because in such a small office you want to be comfortable with everyone there, and it is a great place to work.