What readers love about AIs is that they often really want to understand humans and thus, observe them closely, and register all their body language signals etc. But we have no idea if an AI would be interested in humans. It's just good for human readers if it does.

In this book, Watts does something similar but without AI: there is this person who's lost half their brain by accident, so in order to understand humans, this person needs to observe them very closely and detect all their signals. Unlike we "normal humans" who get these signals subconsciously, this person evaluates all the signals consciously, right before our reading eyes. This was what I liked the most.

But the rest of the story is absolutely great, too. How the aliens move unseen etc. I really like Peter Watts and damn! Just accept the vampire because it's cool and makes sense in this story.