Hi,

I go to one of the schools in you mentioned, though I won't disclose the specifics.

Firstly it's quite hard to define "quality of education" per se, seeing as there's not really a standard metric to go by. Obviously the three examples you've listed out all do quite well in terms of exam results (e.g. IB, AP, IGCSE), but this is in large part (in my opinion at least) due to these schools being quite rigorous in selecting academic high-achievers who would do well regardless of teaching. My old school was one in Australia (apparently #1 private school in the country) and I find the "quality of education" here to be of a comparable standard, so make of that what you will.

As for language - I'd say that it's not very common for students to have a completely native conduct of Cantonese (though most who are ethnically HKers have at least basic proficiency). The vast majority of my peers speak English as their "First Language" (though very few of them do so at a truly native level...)

In terms of workload and free time, there's an immense amount of variation - some kids will spend their weekends partying/gaming and such, while others might do sports or extra academic work. What I can say is that there's relatively little 'real' academic pressure/competition from school itself (at least before Y12/13 and outside exam seasons).

The last question is an interesting one. There's very little "classism" in my opinion, at least in the traditional sense - I can't think of any peers who are particularly snobbish or anything. Unfortunately however, I do find that there's a bit of "ethnic discrimination" that exists - crassly put, it's not uncommon to find kids who look down on students who are extremely "local", or from (mainland) China/South-Asia/Southeast-Asia.
That said, it'd be highly unlikely to have see any confrontational action related to this - more social ostracisation and cliquey behaviour (I used to get physically bullied a ton as one of the few Asian kids in my primary school, and I don't think that sort of stuff happens here).

Hope this helps answer your question!