The company was fine but the job inherently wasn't.
Pros
I worked as a substitute teacher. You were able to get experience teaching with only a college degree required so you could move on to something better that requires teaching experience. The main pro here is experience. You were able to forget about work as soon as your day was over. I only worked at four schools, right next to where I lived, and still managed to have a job every day if I wanted it. My managers were fine, and were understanding when I had an emergency and had to cancel. Don't make a habit out of it though.
Cons
The pay was pretty bad for what you're actually doing. The pay is better if you get a long term position or have a teaching degree but the daily, Bachelors degree path is only a little above minimum wage. You have to worry about the safety of a lot of students, and your own if you teach the higher grades. I only taught elementary schools. Usually you're expected to teach what the teachers leave for you (sometimes they just leave you worksheets) but most of the time you have to continue the lessons. The students think it's an excuse to do what they want that day so every day you have to rework their expectations in the morning. It gets old after awhile. I had a lot of good days though but some bad ones too. If you're good at your job, the schools will start calling you and the students will remember your name. You have less work than a regular teacher, the same safety responsibility, and even less respect from your students, with much less pay.