The oldest and most complete site for Hotel walk-in gals and Walk-up gals and other Hong Kong mongering activities is:
http://sex141.com/en/
http://sex141.com/zh/
Accompanying this site are forums in English
http://forum.sex141.com/eforum/
and in Chinese
http://141hongkong.com/forum.php?gid=59
Yes, there is also a lot of Bait and Switch etc for the gals advertised on the main DB pages of 141. But there is also the forums above attached to sex141 which you could/should check out to make better judgment etc. The English side is more factual whist the Chinese forum is sadly "infiltrated" by the agents - but after reading through it a bit, it should be quite apparent which reports are the genuine stuff and which is just more Agent promo.
Hotel walk-in gals are in Hong Kong for a limited time only - typically less than 2 weeks at a stretch and thus the gals' reviews for hotel gals are only good for a limited amount of time (these are mostly PRC gals who are in Hong Kong on a 2 week two way permit but who are working illegally in the hotel rooms - and are generally of higher quality vs. walk-up gals.) Walk-ups girls usually stay for a longer period of time.
There is also quite an extensive coverage of the action in Wanchai, the saunas, Macau and also China...with Ok coverage in the "rest of the World" section
No harm signing up for the forum/no bots etc. and for those of you planning on mongering in Hong Kong, I would recommend strongly that you do sign up and go through the information therein
Welcome to Hong Kong Y'all!!
SEAJ