Pros
Management was very supportive and diligent about addressing concers. Unlike other ESL schools, CDI offers the opportunity to teach advanced classes (Shakespeare, Ancient Philosophy, 19th Century literature) that are tremendously intellectually stimulating as a teacher (felt almost like a professor at a university). The best students in Seoul will be coming to your school--very intelligent, driven, and in some cases, fluent in English. Excellent advacement opportuities to Head Instructor, Assistant Branch Manager, Branch Manager, CDI Faculy Manager, etc.--something someone could definetly make a career out of if they wanted to stay in Korea. Pay is very generous with opportunities for raises. Offered a substantial raise after my first term (12 weeks) there. Easy hours (4pm - 10pm).
Cons
Do not get a true weekend--it's mandatory to work either Saturday or Sunday, though they will give you two consecutive days off during the week if you like (e.g. Mon and Tues). Don't built much in the way of a skill set unless you would like to continue in ESL education. A lot of teachers complained about the fact that the record your teaching with video cameras and that your Head Instructor will use it to point out weaknesses in your teaching; some teachers also bothered by the prepared lesson plans, feeling it limited their creativity and kept them from managing time how they wanted.