Pros
I think overall, the culture and value of the company is one of the best I have ever worked for. In my many years of doing IT work, and working with bosses, I have rarely worked with the founders that do what they say, and say what they do.
Cons
There isn't a downside. I like working for a small company, I like being able to talk to the management at any time. If you are one that enjoys being a number, this is not a company for you.