Pros
The management and all coworkers are smart, very supportive, enthusiastic people. The benefits are good (housing allowance, plentiful vacation time, health insurance). The work/life balance is fantastic. You can choose to only do your immediate job or take on greater company-wide challenges if you place yourself correctly. You can be honest and open with the management and coworkers. The nature of the job demands many different types of competencies, shaping you into a very well-rounded person. You can spend your time in the office or out of the office and to a large extent plan your own schedule. I can imagine very few jobs that give you as much flexibility and allow for as much creativity as this one.
Cons
Opportunities for promotion come only once in a great while. Some clients can be a pain to work with. Uninspired and jaded students can sometimes dampen your enthusiasm for the work.