Pros
Issue areas, clients, and project types cover a broad range, so if you're the type of person that likes learning new things and not spending months or weeks on the same project or topic, this is a great place for you. The work is fast-paced, and you get multiple "reps" to practice a particular skill. Supervisors are open to your ideas of what you want to work on and how you want to grow. Colleagues are friendly and often happy help with anything you need. You get a lot of freedom -- just get the work done.
Cons
It's a young firm, so there are still processes and structures that aren't established. Again, if you're someone that thrives in that environment, it can be great. But there are times when not having an established process or a set standard can be time consuming, confusing, or create work that looks different across teams.