There was a thread a while ago in which somebody claimed that the Indonesian helpers tended to come from the more affluent part of their society. Can't find it now.
Anyway from today's SCMP:
"Most Indonesian domestic workers are from farming families. They are not well educated. Their will to make money and sacrifice is much stronger, as nearly all of them are from the BOTTOM 10 PER CENT [economically] of the Indonesian population."
Disturbing read as nearly a third are paid below the minimum wage, 60% had their documents seized by their employers or agencies. The maximum amount the agencies are allowed to charge the helpers is HK$318 but 73% were charged between HK$20,000 and HK$24,999.