I agree with this review by Paul Kincaid of the science-fiction collection “The New Space Opera” edited by Gardner Dozois and Jonathan Strahan in which Kincaid notes that the stories presented are mostly not space opera at all and often dull.
Wikipedia states that: Space opera is a subgenre of speculative fiction or science fiction that emphasizes romantic adventure, and larger-than-life characters often set against vast exotic futuristic settings with remotely plausible technology such as time travel and interstellar travel, complex alien civilizations and fictional depictions of the human future.
Furthermore: new space opera, which evolved around the same time cyberpunk emerged and was influenced by it, is darker, moves away from the "triumph of mankind" template of space opera, involves newer technologies, and has stronger characterization than the space opera of old. While it does retain the interstellar scale and grandeur of traditional space opera, it can also be scientifically rigorous
In the collection, the stories were often dark - Stephen Baxter’s piece is set in the aftermath of aliens conquering Earth and driving humanity temporarily insane, but most do not have an interstellar scale or exciting characters. The take place in isolated and contained areas and deal with ideas that are interesting to the charcacters in the story but not the readers.
Many of the authors in the collection have written works of new space opera - Peter F. Hamilton’s Nights Dawn Trilogy is a massive space opera work, and Alastair Reynolds protrays humans facing a galaxy protrolled by machines designed to kill all space-faring life.