It is really hard to make a final judgment on this book. It had some flaws, the whole first half was very slow moving, at times, not uncommon for Barton/Capobianco, the angst factor of the characters so high that it was annoying and I thought, get over it, damn. On the other hand, the exploration of an extinct alien culture through the means of a time viewer was absolutely enthralling.
The reason why they had gone extinct and the connection to the current problems of humanity (in the novel) and probably any sentient race with the means for starfaring was also very interesting, a topic that is dear to my heart and handled by Barton/Capobianco in the best way I can think of doing it.
And while the angst factor was annoying at times, at times it worked well and made the characters quite human, very easy to relate to. So, while I thought the first two hundred pages were rather tedious, the rest was really good and occasionally ventured into greatness.