Pros
I very much enjoy working on so many different projects that are relevant to issues happening in the world today. With only a few exceptions, everyone in the office is smart, friendly and highly motivated. There is a tiny bit of office politics but I think you get that everywhere. A nice mix of working together in teams but not always having to interact with other people. If you are diligent about how you use your time you can create a pretty good work life balance. It is definitely not expected that people work on weekends or stay late, just that you get your work done!
Cons
My one main gripe with Exponent is that there is little room for upward mobility. You really have to push to get facetime with clients and meeting clients on your own at conferences etc. is a matter of sheer luck. There are so many people that have been in the exact same position for 10+ years. That is really demoralizing. To make matters worse they often hire in upper management. I understand that people with contacts and experience in the field are able to bring in more clients but the company really needs to find a way to develop talent from within