Ventajas
A healthy culture that doesn't overdo bureaucracy or meetings, management that will mentor you over time once you've won their trust. You will likely switch between the company's many different projects a lot - this isn't for everyone but I enjoyed the variety. Hours are reasonable and the rules are light-handed so long as your work gets done. The people in the Atlanta office are nice and easy to get along with. The traffic software you work on feels meaningful with obvious real applications. I was there for years and turnover was very low.
Desventajas
Somewhat slow in adopting the latest development technologies and frameworks, though this was changing in my last year or so there (Old technologies are unavoidable with so many legacy products - some of which they were in the process of replacing - so they can't be entirely faulted for this). Pay is on the low end for the industry and you'll advance slowly. I wavered between four and five stars and rounded up to five. But for some people these cons will be more important.