Even the book, especially the fourth book, hit the shit.
George is a good writer but he lacks the stamina to finish a series like Tolkien. Tolkien lived his books. It was his life. George is just a pop book writer.
Four and five would have been pretty good if they were trimmed and combined. He added so many new characters and weird, meandering plotlines. It was his way of stalling for time because he clearly had little clue where to take this thing after the insanity of A Storm of Swords