It depends on your situation. If you think you can stay in usa and get green card or you like to be back to china after some more years, you'd better stay in usa.
You don't need to worry about your legal status any more and you can bedcome citizen here.
So don't come here if you can stay in usa. Come to canada if you cannot keep your legal staus in usa.
For now, you can come here to get citizenship first because it is very hard to stay in usa for gren card. Maybe you will like canada.
You just give up canada if you like to stay in usa and don't care going back to china or illegal stay in usa, which is risky but you get more opportunities in usa.
You don't need to worry about your legal status any more and you can bedcome citizen here.
So don't come here if you can stay in usa. Come to canada if you cannot keep your legal staus in usa.
For now, you can come here to get citizenship first because it is very hard to stay in usa for gren card. Maybe you will like canada.
You just give up canada if you like to stay in usa and don't care going back to china or illegal stay in usa, which is risky but you get more opportunities in usa.