It's Eisner award-winning, it sold well and it's been turned into an animated movie, but I didn't like it. Of DC's two 2005 All-Star series, I prefer All Star Batman & Robin, the Boy Wonder. The Miller one's much-hated, but this Superman one is boring.
Is Superman himself the problem? He's famously a difficult character to write for, but this book shows me a huge additional reason beyond the obvious one. We all know it's almost impossible to keep coming up with meaningful opposition for someone that powerful. What this book demonstrates, though, is that it's almost as difficult to get him mad. He has no dark side at all. No selfishness, greed, etc. Chapter one gives him a death sentence as his cells go into self-destruct mode... and he's not really that fussed. He's too noble to get upset. He just goes on doing his usual thing, albeit with a few twists because his time's running out. He tells his secret to Lois, etc. Before long, I'd almost forgotten that this Superman's days were numbered.
Any normal protagonist would get upset if they learned they were going to die. It generally changes things. Not Superman, though, because he's perfect. (I'm fond of him and I'd get annoyed if DC rebooted him as a scumbag, but that's what he is.) This series didn't feel like a dramatic narrative, frankly, but instead more like a tourist guide to Superman's universe. It's as if we're on holiday. It's fun to be reminded of the wacky ideas and multi-dimensional weirdness, though, even if I almost felt as if I was watching a documentary about them. Samson and Atlas! Descendants of dinosaurs who escaped extinction by burrowing to the centre of the Earth! Beings with an optical language that can blind you if they say certain sentences! Krypto the Wonder Hound! (I love Krypto.) Chronovores and the Superman Squad. Bizarro cube world!
No, I tell a lie. The series comes alive for the Bizarro chapters. Those were good and felt as if a story was living and breathing.
Alternatively, is Morrison himself the problem? I haven't read much of his recent work (and by "recent" I mean "this millennium"), but it's almost as if he's got bored of storytelling. He likes the ideas, but he's liable to skip over the donkey work of telling dramatic scenes and letting a story beat play out naturally. (Or maybe that's just in this Superman book.)
I'm not even a fan of the art. I love Frank Quitely, but this book's versions of everyone tended to look wrong to me. I'm impressed by how he differentiated between Clark and Superman, though. (It's about body language and physicality.)
Alternatively, was my problem simply that I read this collected edition all at once? Maybe it works better as isolated issues? Each one on its own would be a bit pointless, but at least that's better than an entire book that feels like that. Don't see the series as a series. Just dip into it at random and try to enjoy it as a bunch of random love letters to Superman and his universe. Since its chapters don't add up to much, forget that they're chapters and enjoy the deliciously crazy worldbuilding. Besides, the Bizarro material works, so it's not a complete dead loss.