try compare Malindo as well..

I just went with Cathay last week..Its even cheaper than AirAsia.

yes..RM600 for everything..for me definitely worth it with luggage, food, inflight ent, bigger legroom..

checked AA, its already 600 without all i mentioned above.

Cathay can get so cheap? I see about 700+ and from penang some more.

Of course. I experienced it in 2014.
Actually it is not that bad. Strong winds and rain. Most dangerous is the falling branches. Me and the missus purposely walked out onto TST at midnight to see how it was but since we were smack inside HK city, the winds were somewhat blocked off from the many tall buildings. In fact a lot of HK people were out then and there should be tons of photos and news of it in the papers.
I travel to HK at least 3X a year. First time experiencing a typhoon though. And that's why I don't go to HK in December.

Typhoon hitting Hong Kong in December is extremely rare. Typhoon usually hits Hong Kong between July to September. The worst typhoon usually hits in July with the airport closed.
December is fairly safe to be honest. I have transit through Hong Kong International Airport many times in December.