Vantaggi
The only pro to working with Primary Services is that you will be able to put a Fortune 500 company on your resume.
Svantaggi
There are too many cons to list but I will start with the most important. Their pay is terrible. The recruiters just want to fill a job and make no effort to match your skills and desires for your career path with the company. They will make up lies to keep you from getting unemployment between assignments. There is poor communication internal and with the candidates. Their conflict resolutions between the client and candidate are poor, they offer no real guidance or assistance to help you be your best on the assignment. Interviewing with them is often a waste of time as it takes several months before they finally find a job to present you to that will most likely not be in your background or range of expertise, and once again at low pay.