I haven't read the books but the actors are pretty good. Ellie Kendrick was impressive as Anne Frank. Diana Rigg, from the ASOIAF wiki seems like excellent casting. Anton Lesser's good in Vanity Fair, Little Dorrit, and The Hour. I'm happy Tara Fitzgerald is in a popular show, she's done way too little for such a good actor, things like The Woman in White, Jane Eyre, and Waking the Dead.