Pros
No Training, No personal growth, No time-off policies, If client is screwed then you are totally screwed.
Cons
No benefits, No promotions (unless you are so close to managers, You know what I mean), No compensations. One short word, they are leeches and have no respect for engineers. No encouragement from managers, no matter how hard the work you do to get reputations. Managers don't know what they are doing and simply sit at home. They are Shepherd without any directions. The worst part is HR, you won't get a reply that you asked for and often you get when you completely forgot about that issue. As you all knew HR are not meant for Employees, they are for Employers. They never do what's best for employees - let it be in terms of compensation, grievance, appreciation, recognition, you name it.