Finished it. It definitely picked up toward the end. I loved how complicated the Breens' scheming was (some of them really, really want to close that propulsion gap don't they?), and how many folds and twists were brought into play; it became quite engaging. A very well-crafted plot (meaning Mack here, not the Breen
). It was definitely satisfying to see Brex removed from his position after he overextended himself. And I'm amused that after stealing from the Dominion, Tran now wants to steal from the Mirror Universe. Let's see if Pran will wean his people off this obsession with out-propelling the Federation, because this was quite the disaster for them.
There were some very memorable scenes in that final third of the book - Data defending Bacco and Sozzerosz, Esperanza's funeral (it really did justice to the character's death, and I'm glad she was seen as meriting the attention) and Crusher + Picard's last scene, which leads me to wonder if the trilogy will indeed end with the two (well, three) of them moving on.
Finally, the epilogue is a intriguing set-up for book three. I await it eagerly.