Pros
Truly "flexy" work style. When they say to make your own hours they truly mean it, nobody cares when you work so long as you're reasonably available.
Pretty good benefits for the US, such as four weeks vacation and a BCBS health plan.
Kind and fun-loving colleagues around the globe are a pleasure to spend time with.
Excellent culture of continual improvement and learning, people actively solicit and listen to the ideas and feedback of their peers.
Cons
Working across the globe can make for long days (but you certainly can take breaks).
Typical scale-up issues of never having the time to do all that needs to get done (but at least it's never boring!).