I've never successfully had the resort fees waived at the Westin Grand Cayman BUT since some of the services "included" as part of the resort fee (wifi) are also supposed to be "free" with elite status, the resort provides credits to elite guests (either breakfast or F&B coupons) to make up for it.

If you have a choice, I would stay at the Westin vs the Ritz. At the Ritz, there is a greater likelihood you will be staying across the road from the beach as the beachfront rooms are residences and aren't always where hotel guests are assigned. In addition, the beach at the Ritz tends to be very crowded vs the on at the Westin.

Finally, just a personal pet peeve: Be forewarned that, unless the policy has recently changed, the resort charges are NOT counted towards the USD20K annual spend requirement for Ambassador status -- totally ridiculous, unfair and ludicrous. Neither are the charges for services like cabana rentals even though the cabanas are directly managed by the Westin Hotel and not some third party -- totally silly.