don't mean to be paranoid....if possible....might want to check the emergency escape route with these units...i lived in a 套房 in wanchai...there were 3 gates before i could get to the back stairs for any emergency...and the window was blocked by the 去水渠... i moved away form that unit after a month...
use airBnB. iphone App. I know it is very popular in HK. i checked that out before too.
i m not sure if they have Android app though. may be they have website as well.