My oldest will be going to ESF in September. I think sometimes a reason for people not to go is another language, like German, French, etc. I also think ESF has a fairly high percentage of locals, so some schools "look" pretty Asian. To me that's fine, that's part of living in HK, but others may want to have a less Asian feel. They may think quality (of e.g. English) may be of a less higher standard. Classes are usually on the bigger side, 30 kids per class, some international schools have smaller classes. And/or facilities.
Anyway, I am curious to read too!
I am also wondering (but that's just my thought) whether ESF wouldn't have a higher percentage of expat children IF a lot of companies (still) wouldn't pay for children's schools. I mean, we pay out of pocket, it's quite a difference if you pay $60k a year or almost $150k at HKIS. Most people I know who have kids going to CDIS, HKIS, etc. have school paid for by their companies. I guess it can influence the decision if money doesn't play a role (that much). Even though we could afford other schools, we feel we rather spend it on secondary / university education instead of Primary. ESF applications for Year 1 were up 10% this year compared to last as well and Bradbury has a lot of Cat 1 (non Cantonese speakers) on the waiting list, so maybe something is changing in the current economic climate (just guessing though).