Flexibility, ability to work at different schools and with different aged kids. Making my own schedule, having the opportunity to work long term substitute positions for classes I enjoyed subbing for.
What I wish was different
Classroom control, more options for disciplinary actions in between a warning and sending a student to the office.
Advice
Come in early, get familiar with the schedule and student names before school starts, write notes throughout the day to ensure the teacher gets a detailed report of the day.