Pros
Since being hired in 2011 I have been able to move within the company several times. They promote based on merit - not tenure. If you can differentiate yourself, you will have a long and enjoyable future here. Unlike many places I've been employed, if you can work yourself out of a job here, they will find another one for you to try and do the same to, rather than simply saying "well, I guess you're done here." There is also a strong challenge culture. You are encouraged to speak up if you see a different way of working. Your boss, or your bosses boss, are not infallible. They may have the final say, but they expect, when they make a decision, to have the best knowledge available, even if its a contrary opinion. This has been really refreshing to have my input considered, never more so when it wasn't in line with "how its always been done." The interview process is very different. Some feedback on this site has complained about not being job-specific, which is a fair assessment, but not a negative one. KBS is focused on character. If you are a top-notch programmer, but will be a nightmare to work with, not interested. I think this different approach to interviewing shows in the caliber of colleague. I've been consistently impressed with the high level of critical thinking and productivity in the folks that I work with. Lazy and/or disrespectful people don't last long here. Overall, very rewarding experience. Looking forward to many, many years here.
Cons
The expectations for performance are extremely high. You do not coast. If you are not actively engaged in improving the service or customer experience, you are falling behind. It is a fast paced environment, and if not managed well, can lead to high stress. Having said that, KBS HR has one of the best open-door policies I've ever seen, and will always be available to talk through any issues. KBS offers its services to many other companies, and as a service provider, you need to be comfortable never being the customer. This can be very difficult for some.