Pros
Hands down the most interesting work I've done in my career. Lots of creative freedom and independence on project work, for those who are comfortable with ambiguity and are fast learners, the project work is varied and complex- you won't be bored. Many projects have a social impact focus, most prominently in the environment/sustainability realm. High level of transparency in terms of the company health/financials. Good people- staff are generally very helpful to one another and willing to pitch in when things get tight. Regular social events/retreats. Lots of kind, inspring people with diverse life paths and talents.
Cons
Work/life balance fluctuates according to the week/month depending on the workload. Can be unpredictable and very long hours. Slow to let go/passive about staff that are under-performing which puts more burden on other team members.