I love this series and this particular vampire world. I enjoy the different settings for each book and feel this entire world is enriched by the interconnections of person and place. Characters have had serious depth and tangible personalities, and there is consistency in the world-building.
In "Antonio" though, a great deal of time is spent at the start in main character narrative, and if this were a new series or taking the existing series to a whole new place, it would feel more important. In this case, while all of it was interesting, much of it was unnecessary to the whole. As well, the build-up of who and what the main characters were, and why, did not really translate when the two actually-finally-interacted. One, a loner-assassin, the other a berserker-vampire, and a reader could be forgiven for expecting some serious interplay prior to intercourse. Instead, two very hardened and quite lethal personalities with the potential for some excellent repartee, bypassed all of that in a lightning-strike insta-passion. Much of the usual tension and intrigue was missing or marginal. All of which is very uncharacteristic for this series.
I don't see this book as furthering the storyline to any extent; it's more of an interlude. Even the climactic battle has more "anti" to it's climax, and in fact, I was underwhelmed by Antonio's performance there. Dude damn near lost his head - literally - and because of a brain-fart no other Vampire Lord in this series has ever experienced. By way of comparison, it's like...your new and amazing boyfriend puts the toilet paper roll on backwards: on one hand, a boy actually *changed* the toilet paper roll but on the other hand, he put it on backwards (and yes, there IS a backwards!). So, does his attempt at civility outweigh his blaspheming ways? Does he stay, or does he meet the curb? Comme ci, comme ca.
And yet, I love this series and I have faith in its direction. I liked these characters too, and the idea of who they were and how they got "here" was solid, if without the usual flesh on the bones. I must say, I am beyond intrigued by the epilogue featuring the North American Lieutenants, and the attendant possibilities there. It has all the feel of a more complex, intrigue-filled, political maneuvering, clash-of-the-Titans epic. You know: vampire stuff.