Pros
Autonomous work environment with flexible work locations
Cons
In US - No guaranteed annual raises due to letting the clients set the tone for profit margins, no annual bonus, no employer 401k contribution, could report internally to at least 3 managers as well as your client manager weekly, lack of representation with client for salary growth. Know that your work/life balance will be totally dependent upon client expectations and not the company's internal culture so experiences will widely vary based on your client manager.