Pros
Some of the most brilliant people I've ever had the privilege to work with on projects with profound implications for clean energy worked at All Power Labs. I was surrounded by incredible talent in some really arcane fields. The company is small enough where there is a sense of intimacy that I found which I have not experienced at a more established company. Most of my colleagues became my friends.
Cons
The company struggled with cash flow for most of the time I was there, and the engineering team's work is dominated by the ideas of the CEO to a fault. Engineering at this company seemed to have gotten so frustrating for some of my colleagues that they ended up leaving in frustration. The office work flow is also not well managed, and attempts to reform it and streamline it never made it past higher priorities.