I worked in the state school system. It was exactly the same scenario as working in the private ones be it directly or through a recruiter. Cancelled classes because of exams or trips out without telling me, lengthy holidays which were unpaid, no sick pay and ludicrously low salaries which barely covered my living expenses.

'exactly the same scenario as working in the private ones?' Not at all. Cancelled classes without telling me? No big deal! Lengthy holidays which were unpaid? That depends on the contract you signed! Just finished 5 days' teaching on the trot after 10 days' holiday in a row. Lovely biscuits, my salary for June = 18/30 x 5000 RMB for 8 days' work. That is equivalent to (0.6 x 5000)/8. It works out at 375 RMB/day of teaching. And I taught 20 lessons in the 8 days, 2 lessons were cancelled due to a staff meeting! As per lessons, it works out at 150 RMB/ 45-minute lesson. Can't beat that for easy money anywhere, and certainly not possible in the private sector. Wasn't sick, but there was a clause in my contact pertaining to that. Full pay, yes, but only for a limited period, obviously. 'Ludicrously low salaries which barely covered my living expenses?' Your living too well. Cut down your living costs, if you don't mind me saying so. Lesser mortals like me don't go here and there making the rich richer. By the way, though I got no summer holiday pay, I got 1100 RMB for travel and 3000 RMB for my international air ticket for one semester's teaching. Too hot, goin nowhere. Will spend the 4000 RMB on myself locally during the summer break. Doin nothing to help the global economy, ha ha, why should I?
Finally, not every poster in this thread is anti-training centre per se. But there are those like me who prefer working like a real teacher back home in terms of teaching times, viz, no evening/weekend work! You wanna work for a TC, go ahead. But you should understand that one man's meat is another man's poison. TCs are my poison. I'm just stating a fact, not abusing anyone!
I'm very happy with my lot here jobwise, though nothing is perfect, and money ain't everything. I reckon I'm paid well. I'm not after big bucks for more stress and less free time, not worth it in my opinion. Life's too short as it is. Good luck to you, anyway. But in future please don't tar everyone with the same brush. We are not all trolls and bickerers. I reckon I'm neither. You've had your say, now I've had mine. Fair's fair. End of story, I think!