Vantaggi
GMR is a good first job for future engineers and programmers. The staff is pretty nice and it can be rewarding to teach kids. You learn a lot in the beginning but eventually will hit a certain point where you don't learn anymore unless you are motivated to learn on your own. Asking for time off is pretty easy to get unless there is a lack of staff available for that particular day. There is Winter/Spring/Thankgiving Break if attendance is expected to be low due to kids being on vacation. So you can/will have to plan vacations around that if you are the type that feels bad asking for long breaks (2+ days) wait until those periods to plan something.
Svantaggi
There is no uninterrupted 30min. break on weekends, you'll probably have 15 min to buy/warm up food if you're lucky. Setting up for class or talking to parents before/after class will bleed into the supposed set breaks. After 2 years has passed, it's safe to be looking for a new place because you have earned the max pay and be given the highest position you can be. Necessary training to teach more advanced classes and camp will not be paid (which is illegal in CA, but they don't mention that to you) and will be expected to be taken with your free time.