The complain I heard is not about his ability to fix the teeth. But he does not arrange the job priority well. You may run out of your insurance before your worst teeth get fixed. So if you go there, you should discuss with him about which teeth get fix first and how many insurance you have left this year, have him to submit the bill to the insurance company to get a approve before the job is done. In this case both sides will be happy.
I have to say something for him. He is not the one who handles the billing, and does not know how many insurance you have. If you don't tell him he wouldn't know.
I will still go there because he fixed my teeth well. I have to say he is better than any dentist I had in china. It may due to the better technology here. He fixed teeth I thought I would lose and it has been two years.