When my Citibank CX Platinum card came up for renewal I did the sums, and with a 50% fee waiver it made sense to keep it. Essentially the question is "are the extra miles worth the annual fee that is charged". In my case the answer is yes. But I also have an HSBC Premier Mastercard (for free since I have enough balance with them) and obviously I use that whenever I can get the outlet discount since that is always worth more than the miles on the Citi/CX card.

For a while I was making a killing on the Citi Platinum card because they messed up the drafting of their rules, and I had a large overseas transaction every month denominated in HKD which got me 1AM/$4. But after a few months they got that fixed, so now it is worth having, but only just.