I read it last year. It is unlike anything else. Once you adjust to its unique style, it's great.
Things I remember about it: the EXTREME ritual of Gormenghast is a sort of reaction against repressive traditions, and that resonated with me; the characters are vividly drawn; the descriptive passages are more detailed than any I've ever read, e.g., several paragraphs to describe what it feels like to bite into a juicy peach.
The third book is not as compelling, but still worth it.