"Great flaming faculae" !! This is a mediocre collection of science fiction short stories!
The first quote is one of my favorite exclamations from an excerpt of Charles Harness' book the Paradox Man, which is included in this collection. I rate this collection as average because it did not satisfy any urge for conclusion. Several of the stories are excerpts (Sword of Rhiannon, Paradox Man, The Star of Life). So the passages themselves are pretty good overall, but they are just excerpts. So it's analogous to channel-surfing when you don't actually see the end of several movies, and in some cases didn't see the beginnings either.
Given that, the best pieces in the book were the Asimov story, the Van Vogt, and the Harness. I was disappointed in the short piece by Jack Vance (The Mitr), which was printed here in its entirety, as I am a Jack Vance fanatic. But apparently not enough of one to enjoy this story.
There's a lot of scientific mumbo-jumbo and alien names, which is what I expect in the best (worst?) space opera. However, having read it, I have not learned the difference between what Aldiss is calling space opera and what most people call science fiction.