There were a couple of things I loved about this one. First, I LOVE how much more Wild Bill let us know about him in this one. My favorite quote of his (possibly from the whole series, but that might just be 'cause it's the most recent) is at the end when Michael is... ahem, "warming him up" and he says "but through the filter of my closed eyelids, I saw that dappled fairy-light, like sunlight glinting on waves, and I thought maybe I wasn't some kind of bloodsucking freak after all, and maybe good, wholesome things like sunshine and water wouldn't do me in."
That quote just says so much about his personality: that he's sensitive enough to appreciate simple things like sunlight and how it glints on water, and that he believes not being able to enjoy things like that make him evil. And perhaps is some sort of karmic (or divine, since he grew up Catholic) punishment for something? Anyway, it's beautiful. Bill's beautiful. And that just made me love him even more.
The other thing I loved that Bill told us more about was why he was so drawn to Michael. It was fascinating to watch how much he enjoyed Michael's sorrow and angst, and chose to help cheer him up anyway.
I also LOVED that it seems like Michael is growing up a little more. That he chose to not kill Trey because Bill WOULD be around to "feel guilty enough for the both of them." That he recognized that his willingness to kill vampires and the way he phrased his reluctance to kill the human hurt Bill's feelings. That he understood that maybe he needed to find another way to go about his mission of vampire education. All of these, to me, showed that he's maturing.
I want these two to be happy so much! Ever since the horrifically disastrous threesome, it seems like maybe they're taking baby steps toward it. JCP is a genius, I just hope she's a compassionate one and lets these two end happy!