I can tell you a little bit about Beach Blanket, but we only ate there for lunch, and Parrot Cay's breakfast buffet.
Beach Blanket was great because one entire side of the buffet is kids' favorites: pizza, mac & cheese, grilled cheese, chicken strips, etc. On the adults side, there was crab claws, tuna roll-ups, salmon (as you can see, I am big on seafood). There was also a lot of non-seafood selections as well as a pasta bar where they will cook up your selection of pasta with your selection of add-ins. The dessert bar was outstanding, too.
Breakfast at Parrot Cay had pretty much anything you could want: fruit, eggs, sausage, bacon, corned beef hash, bagels, lox, omlettes, cereal, etc.
Wish I could tell you more, but I really honed in on what I liked and never was disappointed or couldn't find something I liked.