If you are considering IC, why not go to IHG forum and look up friends and family rates? for your dates, which I will also happen to be in HKG, you can get IC at a substantial discount using the F&F rate and all rooms/suites type are available, you will not have to spend anywhere near HKD $15,000 in IC.

Keep in mind though, to access the IC executive lounge you have to pay an additional fee but it is usually worth it whiles staying in HKG.

I, however, chose the Langham Place Hong Kong because I got a fabulous 1bdrm suite package including lunch at their Michelin rated Chinese restaurant and a fabulous 2.5 hours couple spa at their well-known Chuan spa all for just under HKD $12,000 for 3 nights. Plus, I wanted to try a different area of Kowloon, off the beaten tourist path this time.