I don't know how I got interested in reading this book, perhaps because I'd been sucked in by the conceit of Ilium, also by Dan Simmons. That book sets the Trojan War on Mars with the gods as some kind of intergalactic beings... but you should check that out for yourself. Because it's a Hugo Award winner, Hyperion seemed like it might be a good read, too. It already had someone else's stamp of approval on it -- we all know that there is plenty of sci-fi dreck out there.
Hyperion has an interesting story structure, using The Canterbury Tales approach of having a group of characters on a journey, each of whom tells the story of what brought them on the journey, using their own words. The most fascinating aspect of the book is of course the Shrike, a mysterious figure who is worshipped as a god by some but mostly feared by all because it is bloodthirsty, made of metal and seems to be able to manipulate time and space in its home range on Hyperion. But I can't even begin to do it justice.
Like most sci-fi novels it takes some time to get used to the jargon that the author has created to describe the technologies available in this future universe, things like "fatline" and "farcasting" and other terms that aren't really explained fully, other than in context. I was really drawn in by the story structure, drawn in enough to continue directly on to the sequel The Fall of Hyperion, particularly since none of the story threads are resolved in the first book after 400+ pages (in paperback form).
Definite recommendation for sci-fi fans who like their stories a little bit dense, surprising and a whole lot interesting.