Landed in HK today. Was looking for 123 prepaid card at airport.
However at 7-11 at HKIA, I got this people's prepaid SIM card for just hkd55. Activated 7 days unlimited data plan for hkd 38. Using it for whole family's smart phones via tithering hotspot.
So far speed n coverage looks good.
My recommendation to use this if u have similar requirements.