From what you say, I don't think you've reached the end of the book yet. It's not as simple as that at all.
Just finished the book and I don't really see anything that conflicts with my original statement. Even Data says that his life before had concluded.
As far as a rating goes, I'd say its average. Solid but not spectacular.
It had a lot of interesting ideas but it bogged down in the middle. Didn't care for the death of Choudhury, just a road we've been down a couple of times already with Worf. It felt repetitive. Have a feeling that it'll lead Worf to question his fitness for command and whether he wants to stay in Starfleet.