Sounds like you have just had bad luck with the training centres you have worked in China, they are normally superior to state schools by a long way. as long as you are from an English speaking country it's training centres every time in China. They are cleaner and basically show you more respect with a few exceptions. This is my opinion. Those teachers from Korea or Russia or with low educational qualifications, state schools are maybe the best option. I do know a couple of good universities in China but all too often they are filthy places.