Pros
They give you enough support to get set up and live in a foreign country. There are lots of expats working for them there, so it's easier to make friends and be social. They also offer Chinese lessons to all their employees. The job itself isn't difficult, as long as you have a decent grasp on English and how to teach it. The salary is enough to live quite comfortably in Shanghai, go out in the evenings, shop a little and travel too. You likely won't save much over the course of a year, but that's by foreign standards, and is due more so to the exchange rate than the salary.
Cons
You're going to be mostly on your own to find housing. They gave me 2 weeks in a hotel before I was forced to find my own place, which can be a bit expensive if you haven't made a friend to search for an apartment with yet.