This book offers a new twist to the topic of exploring ruins and technology left behind by the Ancients. The Quantum Mirror is a very interesting idea as are the - kind of - mirror Wraith, the Eidolon. I think this idea would also benefit the Stargate Atlantis TV series.
Some parts of the book are impressive. They deal very well with the mutual distrust, the trouble on both sides to work together and understand each other. On the other hand, the book could have been so much better. It suffers from the problem so many ensemble stories have: In spite of some highlights, I would have liked a more detailed, more personal examination of how people actually feel by having to work together and having to fight the Wraith. There is a lot of action going on but I would have preferred more emphasis on characterizations and interactions.
I expected it that the three male Eidolon who helped would be out of the picture very quickly. I regret it that I was so right. I would have expected that the book features Ronon very strongly, but that opportunity was wasted. He was not much more than a background character, which is a real shame considering what the topic of this book is.
I also would have preferred it not to see the Wraith described as "it" again (except maybe the drones) and allow them to show a bit more intelligence as given in this book. The Eidolon Queen manipulated the Wraith MUCH too easily. The book could have been much more interesting if the Wraith leaders would actually have been a challenge, not only as space vampires and thugs but also on an intellectual level. But, of course, it is easier this way to put the climax together and end the book.
I liked the book but unfortunately there is a lot of wasted potential.