Planning a 5-day visit to Hong Kong, with Disney Land being the main destination. I have an American Express card that I rarely use, and I would love to abuse it in this trip.
Is American Express widely accepted in Hong Kong?
I just consulted some friends who live in Hong Kong: no, Amex is not widely received in Hong Kong at all. In fact, not even Hong Kong Monetary Authority's centralized payment system (Faster Payment System) support American Express. Only perhaps high-end department stores, luxury hotels, and restaurants catering to western guests take them. Better forget about Amex in Hong Kong.
I still like Amex, but the reception of Amex is spotty at best outside the USA. If you really want to abuse your Amex card while in Asia, I suggest you do so on a trip to Japan, since Amex has a reciprocal acceptance agreement with JCB in Japan and is thus quite commonly accepted.
It's better in Hong Kong than in mainland China but it's not great. You can certainly use it in hotels and high end stores & restaurants, but I highly recommend bringing a Visa or Mastercard as well.
Personally I tend to avoid stores and restaurants in China/Hong-Kong that accept Amex since it's a clear indication that they are overpriced and have high mark ups. Amex charges the merchants significantly higher fees than Visa or MC. One way or another the merchants need to recover those extra fees. In one hotel in London I had to pay 3% extra for using Amex instead of Visa/MC.
In my opinion/experience these days Amex has no benefits in terms of insurance, rewards, points, cash-backs, support etc., they are significantly worse in terms of cost & fees and acceptance outside the US is spotty at best. Time to dump them.