Elle is right. Those are just stereotypes, and not great ones at that. (Since when was the ability to take bad treatment considered a good thing?)
There are some nationalities let in on domestic helper visas -- Filipinas, Indonesians and Thais, for example. I find that the Filipinas (mostly) and some Thais are more common among expat families. The Indonesians speak some Cantonese, so are more popular among local families. But those are broad distinctions, and it's most important that you find the woman best for you.
The difference -- to answer your first question -- is that Mandarin-speaking Mainland Chinese are not here on DH visas, so they are totally a different kettle of fish.
There are some nationalities let in on domestic helper visas -- Filipinas, Indonesians and Thais, for example. I find that the Filipinas (mostly) and some Thais are more common among expat families. The Indonesians speak some Cantonese, so are more popular among local families. But those are broad distinctions, and it's most important that you find the woman best for you.
The difference -- to answer your first question -- is that Mandarin-speaking Mainland Chinese are not here on DH visas, so they are totally a different kettle of fish.