FYI, there are often sales at the HKG duty-free Gucci (and other) stores that aren't in the boutiques. When I was in the Hermes boutique advising that my wife saw something at the duty-free that the boutique didn't have, they explained the duty-free boutiques are run by the contracted (read: paid a whopping amt of $$) retailer, which really acts as a middleman.

Not sure what other tips you wanted as there is no haggling at these places. You might see some so-called "outlet" stores at Kowloon station and other places but, generally, these places have crap stuff (which some look fake too).

As for watches, unless you know someone (or someone you know happens to know someone), most stores are probably unwilling to discount much.