>> Don't expect to have a discussion about what cards are good for what, etc.

If you speak Cantonese, they will tell you. Certain vendors are are very reliable and hence popular.

if you do not speak cantonese i'd suggest you bring a friend who does or go somewhere else...vendors there are not known for their english proficiency. hell they can't even express clearly in cantonese what the sim cards do or do not cover!

You might also want to check whether your hotel (if staying at one) offers the free portable wireless hotspot / phone that you could just tether to. For example, the Sheraton HK offers these.

DO confirm with the hotel of the availability of a loaner local phone/hotspot. I heard rumours that the provider is going out of business

Marco Polo also provides a free hotspot (read: cellphone with tethering capabilities) with their rooms.

I just went into a normal shopping mall mobile shop and picked up a Sun mobile data sim for $108 HKD (about £11 GBP or $14 USD) 12 Gig of data and valid for 30 days. Shoved it in a MIfi and it's working perfectly with 4G. Chap spoke decent English. Mall is in Tung Chung just by the airport.

GOOD DATA POINT - this seems to be the best deal for 30 days of heavier usage
Did you remember whether it was a b=generic mobile shop or a "SUN" shop?
Can you post an image of the packaging if you still have it?

The shop was Telecom Digital Mobile Ltd. Seem to have shops elsewhere in HK. Website is ? ? - ????

Don't have the packaging, The receipt says
30 Day Always On Plan
Flex-mobile Sim
106 HKD. (even cheaper than I thought)

We've used it to synch a load of stuff on and off dropbox when on a client site where we don't have use of their network and it's been great. Think I used about 8Gb in a week (accidentally let the laptop run an update as well).

SUN runs off CSL.
They are a big reseller chain. Many "SUN" stores around town.

For anyone interested this is the link:
Flex-Mobile

Seems like the best deal for the heavy user in HK. These outlets should have better English speaking help than the street vendor at Duck St (Apliu).
Also reasonable top up there is no need to open the mifi to toss the used up card and replace.

SUN
 

SUN / Telecom Digital Flex-Mobile sim review

• It is $106 HK for 30 days of service, 15GB at 4G speed plus other SMS and calling. ^
• Have not found any dead spot yet aside from X-Harbour tunnels. ^
• Store attendant suggest just come in and buy another card as top-ups are in increments of $25. Cheaper to toss and replace unless the phone number is important to you. I use this in my as back up mifi so the phone number is not important to my usage.^
• English proficiency at store better than Duck St or most other street vendors.^
• You get a real receipt (if that is important to you) ^

• After 15GB it drops to 128k. :td:
• The 30 days starts when you make the purchase. The card/plan is activated at that point. :td:
• Only available in person at the store, the store does not have order ahead service as the SIM is activated when sold.They are not prepackaged. :td: