Overall HKG has the best luxury hotels in the world, so you cannot go wrong with any of the top 10, even the top 20 -- making the specific choice not so crucial. Getting objective advice on this from the web is difficult because everyone has different criteria for rating hotels; for example the RC gets high marks from many people because it has an excellent club with great food; but irrelevant if you don't stay at their club level or don't care about free food at strange times. Similarly a few hotels have fabulous swimming pools (Pen, IC and Sheraton pop to mind) while others have pools that are almost unusable (RC for example). If a specific feature matters to you, then do research, otherwise pick based on location and price. Prices vary a lot based on occupancy rate, and that in turn is governed by what trade show is on that day (I've seen 50% fluctuation in price for the same hotel a few days apart, though that is an extreme example).