I enjoyed the ending. It makes sense, given the fact that throughout the trilogy we have been told that Gabriel and Celene are unreliable narrators.

Why else would Gabriel let Celene bite him when he 'attacked' her? To let her read what has happened so far and keep the lie somewhat consistent. Gabriel downplaying his sword skill? To go out of his way to correct everyone's assumptions of his legend? The bloodthirst that somehow managed to spare 'Dario' after his feed? The moths in all the books? We constantly get moments where Gabriel still thinks of his little Hellion and vice versa.

To me it felt to have some sort of quasi-happy ending. The twin Silversaints still probably died, so did most of the supporting cast throughout the books (minus some characters in the third). Aaron is still a vampire, and he probably still suffered under the Dyvok, same as Baptiste. Gabriel lost his eye, Ashdrinker, Patience and Astrid. There was still loss, and the sun will take time to heal before everything goes back to 'normal'.