I first tried to read this many years ago and couldn't finish it. Yet I continued to hear good things about so I eventually gave it another try and this time managed to finish it but still wasn't too impressed.
Lying somewhere between fantasy and horror, not quite succeeding at either, it falls between two stools. I didn't like the protagonists who, it felt to me, were swept helplessly along in the plot without really contributing anything.
Since reading this I've read a bit more of his work and I've come to the conclusion, with one or two excptions, his writing is not really for me.