回复：我是在美国等候好，还是回国等更好？

You do not need to worry anything at this stage. What about going back to China to take a vocation? I had similar experience as you are. My J1 expired 2 years ago, when waiver was still pending, even no objection letter was not send to DOS. I went back to China, waited for waiver as well as H1b petition. The visa procedure in Beijing went very smoothly. I think your coming back to China on time justifies you quite a lot.
Take it easy, Go back hone to relax!