I didn't feel entertained by the first book, as it was mostly setup, but there were quite a few ideas that hinted at great things to come, so I felt that the potential for greatness was there. And indeed, The Fall of Hyperion explodes into a myriad of interwoven themes: artificial intelligence, politics, religion, poetry, the evils of the technological world, the wonder of stars, the search for and/or manufacture of God, time travel, interstellar travel, speciation, reverence for nature and the human spirit, philosophy.
And yet, my feeling was that somewhere between the potential of the first book and this second book reveal there lies the potential for a far better story than what I've got. The Fall of Hyperion felt an old man's story, full of fear of the future, unrealistic expectations from humans, an unhealthy dependency on religion, the myth of the human spirit and last century references. Even worse, the characters were hard to sympathize with, at least for me. I didn't feel their motivations, nor did I understand the instantaneous switch from acquaintances to friends one would give their life for. The blending of vague philosophical musings and poetic references, plus a less vague description of the world which felt quite outdated didn't help.
That's why it took me so long to finish this. To be honest, sometimes I would just fall asleep with the book in my headphones and didn't quite go back as far as a point that I would fully recognize, so basically I skipped parts of it.
The first book felt like something someone would have written in the '70s and then thought about it and reedited it and so until its publication in 1989. The second book feels like it was written in the '60s! It's not just that I didn't understand parts of it, it's that having not understood them, I didn't feel the need to.
And there are two books - just as large - left in the "cantos"! However, since most of the story arcs of the characters in the Hyperion books have ended, including for the planet itself, and having seen that the other books happen elsewhere (Endymion) and the third book was written six years after the second, I assume that it's basically another duology in the same universe. As such I don't feel compelled to read the last two books. Maybe they are better, but I want something else for a while.
Bottom line: It's a very complex book, one that I am sure took a long time to consider, write and perfect. I just didn't care about it one bit.