Pros
First of all, there's no corporate headquarters. Everyone works from their home. Collective2 is a tiny company, and apparently is proud of that and intends to stay that way. The founder thinks organizations of a certain size (exactly what that size is, is not entirely clear) are dysfunctional, full of politics and frictions that small teams do not have. Everyone at C2 has a lot of power and responsibility. Programmers are expected to wear "business hats," and business people are expected to at least understand programming constraints, and everyone is expected to be a product developer.
Cons
The bad stuff is the flip side of the good stuff. Everyone works from home. If coming into an office and playing foosball with colleagues is important to you, this company is not right for you. The whole "virtual collaboration" concept can be lonely at times. The company is small and intends to stay small - the owner has no interest in an IPO or a corporate acquisition, so if you are looking for a financial lottery ticket, this probably isn't it.