Pros
The large number of highly motivated and intelligent students make teaching here highly rewarding, and good teaching tends to be recognized and praised on their part. The time commitment is also not excessive for most courses, and it's easy to set boundaries between your teaching work and your other obligations. There is also a reasonable amount of flexibility in choosing which courses you want to teach, though this might vary from department to department.
Cons
Though the majority of students are interested in learning and mastering the material, there are always a few who are just interested in getting the good grade and making sure that the class takes up as little time as possible. This often depends on the class you teach, and doesn't happen frequently, but it can be frustrating when encountered.