Pros
Because it is so difficult to become an FTE (full time employee) with the government, many people opt for contract agencies like Kelly. I've been with them for a year-and-a-half now and have no complaints. It's a good option for people wanting to get their foot in the door of the federal government and I've had absolutely no problems during my time here. Although I am employed by Kelly, I'm assigned to a federal agency where I essentially report to my government supervisor as I would in any other job. It's a pretty painless process and I have no complaints.
Cons
It's hard to find any real negatives to working here. I've never really run into a problem in my workplace so I haven't needed to call on them for anything aside from basic human resource issues. I guess I would like to see better (read: more flexible) health insurance options (you get to choose from three) but everything is costly these days and I know I still have it better than colleagues who work with different contracting agencies.