Pros
With around 14K employees, King County is a big "company" with lots of opportunities and a wide variety of projects. Since the county is not profit-driven, the management practices aren't cut-throat like you experience in many big companies. The projects bring you a sense of doing something to help the community. Vacation time is so-so, but the rest of the benefits are stellar. If you want to leave your stamp on an IT department, this is a great place to be. Projects are moving toward Agile, and that's leading to opportunities to influence how the methodology is implemented. I do like that while there are templates for various stages of projects, there's a lot of leeway to do what's the right thing for a given project, and then to share what worked and didn't work with the rest of the team. The office is in downtown Seattle, but you may need to spend time in Kent or Renton based on the projects assigned. Everyone is in the same timezone, so there aren't meetings scheduled at 5am Pacific like you get for companies where HQ is on the East Coast. This is either a pro or con depending on your point-of-view: Business Analysts get a chance to be Project Managers and Scrum Masters because those functions aren't fully staffed right now.
Cons
This is definitely a buy vs. build shop, with an emphasis on off-the-shelf solutions. PMs and BAs spend their time on RFIs and RFPs. Vendors are selected to implement and customize solutions. Therefore this isn't the place to sharpen your coding skills, but it is a place to become familiar with big vendor solutions. It takes a while for projects to get approval and finally start. Some projects have an immediate sense of urgency once they're funded, and with others you wonder if the PM cares because they take forever to plan a kick-off.