I voted poor which is probably unfair as there was much to enjoy about the book but I personally don't agree with the approach taken with Sisko and it overwhelmed all the positive parts of the book for me in the end.
I can't say I was particularly looking forward to this book as I have no interest in Spock or his movement but I was pleasantly surprised how engrossing I found it. I was surprised how easily the Romulan Empire was reunited but overall it was well done.
The Sisko storyline felt out of place here though - it didn't really have much to do with the other storyline and someone else could have been sent to Donatra in his place without the book losing anything. Also the Tzenkethi flashback seemed somewhat pointless - it wasn't clear why it was there at all.
My main issue is the decisions made about Sisko & to a lesser extent Kira which for me personally seem at odds with how these characters have been portrayed over the years. Sisko faced down the sorrow in the show - bringing it back now just jarred for me and having him abandon his family seemed a complete betrayal of the character and the actor.
Perhaps if we'd seen the events that supposedly pushed Kira & Sisko into these actions then it might have worked but it just came out of nowhere here. Again this isn't the writers fault - the time jump has been decided on and he worked around it. Maybe if we get a book filling in the gap it will make these developments more acceptable in the same way that Full Circle did for Janeway's death.
So a good book in parts but the Sisko section really didn't work for me and at the moment I'm not sure if I want to read any further DS9 novels given where the characters are right now.