Pros
Lots of great friendly co-workers, free snacks/drinks, dog-friendly, casual dress in the office (more business professional on client site). I enjoy being in the office.
Cons
Benefits and compensation aren't anything to brag about, most people make below market and there's no 401k match.
The CEO will absolutely never accept blame for anything. Ever. Even when he should just to save face. There is always a chance that you'll get staffed out to Microsoft and never see the office or your Piraeus co-workers.
Development practice is out of date: only Microsoft stack (not many new frameworks or languages), no code reviews, no design cycle, no quality assurance process. Developers are expected to test their own code but hardly ever given enough time to do true unit testing. As a result, buggy products are shipped, but great news - then the sales team can sell a version 2!
Sales team is only good at selling to Microsoft and to existing clients. As much as we spout the words "true consultancy" and "workshop consulting", we are at our core, a Microsoft vendor and staffing company.