Pros
I imagine there are few companies of this size (~1500 employees) where anyone can share their thoughts openly about how things are handled internally. Upper management is very open to feedback; it's only those that choose to be quiet that aren't heard. The company is serious about its people and ensuring the unique culture is protected. The work/life balance is great--people bring their dogs into the office, workout together at lunch, and spouses/significant others are always welcome at company events. Personal development is a serious commitment, so much so that personal goals are tracked and figured into annual reviews.
Cons
Just as it's exciting to work for a company that feels like it's constantly evolving, it can also be frustrating. Often it's apparent when strategic initiatives are put in place and fizzle because they aren't as effective as anticipated. Sellers have to endure some difficult outcomes with projects because the organization has to stumble before it can find its stride as a true professional services company.