Disagree. At renewal I did the sums and at HK$900 it made most sense for me to keep the Platinum for the benefit of double miles for overseas expenditure. But if you don't have much of that then I guess it wouldn't.

(1 extra mile for each US$1 of overseas expenditure. The "price" per mile goes below US$0.01 at expenditure of around US$12,000 per year.)