I have to say, this was a refreshing return to what I'd come to expect from the Titan
series after the first three books! The characters were allowed to act out the story and draw the reader into it, including the Sentries' civilization, instead of the characters being subordinate to somebody's worldbuilding (a la Michael Crichton/CLB in Torrent Sea, or the A-plot of Sword of Damocles). While some science is always interesting and good to see, if there are no engaging characters, as far as I'm concerned there is no story.
But in this book, even the AIs were engaging, and I found myself wanting to know more about their personalities and pasts, and caring about what will happen to them after the Titan moved on. In this regard, I have to disagree with the previous poster who said they wished the avatar had stayed instead of White-Blue: I think that in White-Blue there is sufficient material for a character that can be developed.
And I'm just BURSTING with a story idea/connection that I know I can't share here, but I think there's real potential for what White-Blue could potentially assist with given his actions that we saw earlier in the story. If anyone (not a Trek author, of course) wants to know, shoot me a PM.
Even as someone who found no compelling reason to read Destiny (I quit caring about the TNG relaunch awhile back), I thought it was excellent to examine the effects that the Borg Wars continued to have on the Federation as well as on specific individuals, and how that colored everyone's reactions to the Sentries.
Now, as I'm sure everybody either knows or could easily guess, one of my favorite characters is Zurin Dakal, and I have to say, I really loved seeing how much more he's come into his own since his early difficulties trying to fit in. He still has that same quiet, introspective nature, but he seems a lot more confident in himself and that was wonderful to see. And I also appreciated seeing him used as kind of the "voice of reason" on multiple occasions instead of what could've been the stereotypical "Cardassian"--suspicious, ignorant of life outside the Union, and having a cavalier attitude towards life unlike his. That's a mistake I have seen a few authors make with him (using him for little other reason than to have him stick his foot in his mouth), and it was good to see things NOT go that way for him.
I have to say, though, I felt VERY sorry for him when he got hurt, though! Just one question...was it just his hand/arm that was mangled by the transporter, or did he have other internal damage as well? Or if not, what was it that sent him into such bad shock later--just the trauma, or was it also putting a strain, say, on his circulatory or immune system to have his flesh merged with foreign material in that manner? (And THANK YOU for not killing him!)
My one quibble, though, comes with the cover art--heck, I was actually leery about the content of the book because of the art! (A worry that thankfully, I was able to put aside.)
I get the distinct feeling that, while the art was quite attractively done from an aesthetic standpoint, that the artist did not actually read the book and was trying to play Synthesis as a genre that it's not. Had he/she actually read the book, I think the discomfort Riker showed with the Minuet program and the avatar's form--especially given his love for Troi--would have been enough of a reason to NOT pose Riker and Minuet in that provocative manner that almost makes it look like Riker's contemplating a tryst. He was doing nothing of the sort; that's very clear from the book. And it was almost like the artist was trying to make the book look like a Harlequin romance, which it was not.