Following on from your recommendations I've been on the look out for his works and have recently read Fugue for a Darkening Island which I found quite interesting, if a little tonally odd at times. It certainly made me want to read more of his work.

I finally found a copy of The Separation just last Friday and picked it up considering all the good things you have said about it. I've a couple of things to read before it but am quite looking forward to reading it.