Pros
Depending upon the client, you may enjoy a flexible schedule. Opportunities to learn new technologies and always new problems to solve. Great coworkers who make the challenges of working here bearable. Very good overall compensation.
Cons
Historically, the company over commits to client work and the staff often have to work excessive hours and deal with very stressful engagements. Despite some occasional nice employee perks, the technical resources can be treated like factory workers. Zero career growth. Promises of raises and career advancement are not kept.