Pros
Working at Steampunk has been a great experience. Despite recently transitioning to a mid-large size company, the small company culture still exists allowing you freedom in how you work (your not nailed-down with the micro-management or bureaucracy you may find in another, larger company), but it's still large enough to have all the resources you need (and more) at your fingertips right when you need it. Also, they're really good at picking good team-members. I've never worked at a place so long and found everyone I worked with to be compatible, purpose driven, and genuinely good to work with. Overall I think it's a really great company to work for.
Cons
Its a growing company and there are sometimes areas of ambiguity and/or the need to step out of your comfort zone and be flexible with the work your doing, but overall the benefits outweigh any potential negatives.