Have an upcoming stay in San Diego and trying to decide between Hilton Bayfront, Hilton Gaslamp, Embassy Suites or Doubletree Downtown. Not parking a car - all locations are suitable. Total cost for the first three (including tax and fees) are all within a couple dollars of each other and the Doubletree is $35 less. I am a diamond member. Are the diamond breakfast credits stackable with destination charge food credits? Given prices are all the same, which provides the best experience?