Pros
They will send send you out to many school districts, you will get much exposure, everyday is a challenge, and every assignment is different.
Cons
They have monopolized substitute teaching at practically every school. Before every school secretary hand selected the substitutes for the assignment that most fitted. They do not mention that you will be evaluated at each and every assignment and that these evaluations are based on statements that are OPINIONS (How can you evaluate a substitute based upon a one day assignment). They do not tell you that the school may be located in a high crime zone and that the school may have gun detectors. The administrators at these schools, that S4T sends you to, make unjust acquisitions that can damage your work history. S4T operates unfairly. Its all about money.