Pros
Challenger has some great students. They are smart and for the most part dedicated. Class sizes can vary, but at the smaller campuses they are terrific, with classes often below 20 students. Larger campuses have more students per class but are able to be choosier about students, so the quality of students and thus the classroom environment is higher. Compensation is good for a non-union school, though unionized public school teachers make a lot more after a few years. They have a philosophy that strongly supports individual effort and achievement, not a "feel good" focus on self-esteem through a lack of meaningful feedback.
Cons
Do not expect loyalty from management. Their philosophy is that the curriculum teaches itself and they can always replace a teacher. Management has a fearful attitude towards technology - teachers do not have company email or internet access while on campus. There is no option for video or a computer projector in class, and even when teachers are willing to provide their own they are forbidden from doing so. Benefits are limited and expensive. Fear of liability often leads to a great deal of control being placed upon students, which undermines the philosophy of individualism. The focus on curriculum time does not account for students' need to break focus or to just get outside and blow off steam. As a result, students will drop their focus when they need to, which is often in class. This seems to result in students not developing self-control and instead relying on control to be imposed upon them.