Details: (c) 1966 Ace Books Inc; Pub 1996 Ace;
Verdict: Empire Star is delightful!
Reasons for reading it: My reactions to the Delany I've read so far range from enthusiasm to intense awe and joy, so I had high expectations of it.
How it came into my hands: rysmiel pointed it out to me when I was going mad buying books in Montreal. I'm not sure why I've left it so long to read this given my regard for Delany. I think I was put off by the strange format; two novellas packaged together is fine, but printed so that one is upside-down relative to the other is disproportionately irritating.
I read Empire Star in a near-constant state of "ooh, cool!" The surgical precision of the language, the exciting adventure, the really solid world-building, the characterization, the cute in-jokes, the emotionally effective writing, the philosophical bits, the excellently paced reveals, just so much squeeworthy stuff.
If I had to pick one exceptionally cool aspect out of all this, well, I couldn't pick one, so have two. Firstly, the sensation that Delany and very few other writers evoke, that he has created this fascinating, detailed galaxy just for me to play in. I could easily believe that there's enough detail imagined for a book ten times as long, the setting seems so consistent and plausible. But the detail never gets in the way of the story; I think the reason I believe in it so much is because it is so subtly in the background, so reading feels as if I've always lived in this setting, rather than encountering something that is being shown to me by a proud creator.
The other thing that's even cooler than the way the book is generally cool is that it is essentially a time-travel story, and it makes the time travel paradox stuff both sensible and novel. Again, I almost experienced the twisting of reality that happens when time isn't linear, rather than just reading about it, or even reading characters having the same discussions about the implications of time travel that have been repeated since HG Wells.
I think this length suits Delany well. It's long enough to establish a complex and detailed plot, but not bloated with a lot of philosophical rambling which is probably Delany's biggest weakness in those of his books which are merely good rather than great. I can't even complain of disappointment that I ran out of book so quickly; it's just exactly the right size because every word contributes to the perfect structure that you only realize was built up when you look back. If I were being hyper-critical I might complain that the ending is a teensy bit rushed, but expanding the list of other adventures would have made it unbalanced.
Basically, Empire Star is the kind of book that makes committed SF fans really happy. It's also very good writing, so it made happy for other reasons too (I'm only sort of an SF fan).