Pros
The company is very transparent. All-hands meetings happen regularly with very open Q&A sessions. A lot of effort is put into collecting feedback from employees and customers, improving efficiency of communication across the company and communicating decisions and their rationale back. Despite occasional changes in leadership, massive growth, and several events that might cause most companies to become more secretive, the company has remained this way: very open, and upfront. Most employees are very passionate about the product and what it can do. All managers that I've worked for or known well are very invested in helping their employees be effective, and balancing company-wide goals with individual interests and ambitions. Although the company is not perfect, people tend to be open to admitting that, are aware of the short-comings and work to correct them in reasonable time frames.
Cons
Sometimes there's a bit of cultural rift in the company, between projects that are open-source and projects that are proprietary. The company has an excellent policy for deciding what should be proprietary that I think most people are aware of, but there's still sometimes a gap in how teams want to work or how the individual team members are used to working as a result. It's been a long time since I saw this causing any real problems, though.