Pros
Any time I'm contacted by a recruiter for a job that seems interested, I get in touch with PSCI to see if I can work with them instead. Great company culture. Focused on long term relationships with both customers and contractors. Many of their contract workers have been with them for more than a decade. They are very flexible, I was able to sign on as a full employee while on a contract assignment and actually get vacation and holiday pay. Their contract deals seem to be a win for everyone involved. Cobra after the assignment ended was better and cheaper than the health care at my subsequent permanent position. I've worked for a couple other firms and actually told one company where I was a contractor that should dump the firm that had placed me and go with PSCI at the end of the initial contract as I was sure that they would save money compared to the national firm and I'd be a lot happier.
Kontras
Since Glassdoor is making me enter a con. They are a fairly small outfit and don't have access to all the opportunities that the big guys do.