Kingston vs Yew Chung

I do hear good comments on both schools through friends of friends but do not know personally anyone there. However, when I read through earlier posts, some people raised serious concerns on the standard of English of Yew Chung, that the level is nothing near other IS.

Kingston also has mostly HK families with kids speaking mostly cantonese outside campus, just like Yew Chung (and i guess the background of families is quite similar). Would kids from Kingston face similar problems, that they would have problems adjusting to an all english environment Would Kingston parents provide any insight?