Pros
Pretty good work environment, though they have fallen for the open plan scam like so many others. Willing to use new technologies and are open to ideas for improving things. The faster pace keeps things fresh. Not too much red tape to get things done. Significant investment in infrastructure like servers, networking, hosting, virtualization. Free lunch and drinks every day.
Cons
Stuck in startup mode even though the company has grown 500% in the last 5 years. Mountains of technical debt without real plans to improve it. Losing people to attrition over the last several years without replacing them has left teams small and often overworked. Testing and QA is scattered and not a priority at all. Benefits are very mediocre with no 401k matching. Development management is musical chairs that changes completely every 6-8 months. No real career paths except for sideways.