You need your passport and many but not all bank can do this in the center of the city. Waiting time at the bank can be long so I prefer the airport for the small difference in pricing.
I heard about these machines too but never saw one.

The machines are the way to go for smallish exchanges.

DO the machines in China surcharge like the ones in Thailand (with an additional surcharge) such as the THB 150 or 180 or whatever it is this week in the Kingdom?

Although I too have not come across fake bills, I do believe they exist (not sure if they are more common than fake US$20 to be fair).

Re: fakes from an ATM, my understanding is that unlike western ATMs that take deposits and give withdrawals, where the two transactions are completely separate, in a Chinese ATM, the cash for withdrawal draws upon recently deposited notes. In which case, one could end up with fakes. I've heard it's best to withdraw from machines that don't take deposit, but I have withdrawn hundreds of thousands in cash and not had any problem.

tb

I have not found there to be an ATM fee in China (not saying it doesn't exist, but not on the many ATMs I've used).

Of course, your bank may charge a fee for withdrawals from a "foreign" ATM.

Actually I have heard of a case where someone put fake bills into a withdrawal only machine. However, I do not think that it is possible for it to be withdrawn by the next person.

Basically the trick is to do a withdrawal, take the notes out, then quickly put fake notes back in. The machine will think that you didn't take your money and take them all back.

I remember that used to work at the Chuck E Cheese (kids arcade) when I was a kid, didn't think an ATM would fail like that.........