Hi, I stayed at both properties Spring '05. I am only SPG gold and we received a wonderful upgrade to an Ohana suite on an award booking at the Sheraton. No upgrade at the Westin. We loved the Sheraton and would stay again without hesitation, even without an upgrade. The only nice thing about the Westin is it's pool. The Sheraton was much more relaxed and seemed more upscale. You can't beat the snorkeling at Black rock right on the property too.