1. They are bias, they are set on the British system, that is why they often ask their teacher's to have a Cambridge Certificate (CELTA)
They ask for any TEFL, as long as it is recognized.
They teach American English. How is that 'bias', and what is wrong with choosing one system, whether British or American?

2. They pay too low for more work. There benifits are not so good, many other Chinese companies offer a better deal.
They pay about the standard rate for private schools in most cities. They offer airfare, and some now pay bonuses.

3. The are corporate, meaning they expect you to follow their orders and do things their way, no personal teaching creativity, "Do it the EF way!"
- Unlike any other school who will tell you to 'do it your own way' I presume?!

4. They are in the business to make money, not really to teach, profits come first, so the teachers at the "bottom" of the ladder will get a lousy contract compared to if they worked for somone else in China.
Other private schools aren't there to make money I suppose?
Teachers all (should) get the same contracts, though pay goes up if you sign for a second year.