My son is attending their international playgroup which is located in Tsing Yi Garden.
After 2 months, he has made significant progresses. He "talks" more (actually he babbles), sings more, seemingly very happy to attend class every day. I guess he enjoys school life there very much.
Teacher emails us, tell us what he'll learn each month (with a theme). Also, send us updates on his progress (sometimes with photos). If my son is absent from class, the teacher or staff will phone me to see what happens.
Also, the son has a clear book showing what he has been taught in school. Like in last month, the theme was school life, and now it's body parts.
Besides, every week or so, he'll bring an art folder in which his artworks are contained to home, like paintings, drawings, handcraft etc.
Personally I find it is a good school to go, though it is international class which may not be exactly giving you an answer to your question.