The characters were all well drawn and fully realized. None of the main characters were hollow caricatures, and even the secondary characters felt real. I was fully invested in Nick and Natalie's relationship, and the success of their venture. I loved Corie, and Nick's mother.
The romance built realistically enough that I'd call it a love story rather than a romance - except that it really did move quite fast. If I had one quibble with the story, it would be that the flow of time was a little confusing to me. There would be mention of days passing, and the work on the property progressing at super speeds, and then come to find out only a couple days had passed when with the amount of stuff going on it felt like it had been weeks. Probably distracting enough to knock off half a star.
I liked getting inside the bad guy's head - it really kept the suspense up for me. Early on, I thought I had worked out who the Slayer really was, and I thought that it would be quite the feat to pull off, but turned out I was wrong. LOL
As for content, there is mention of faith, but it did not feel in any way preachy. This is a clean read - one that doesn't stand out as clean, in that I wasn't thinking, "oh look, she replaced this dirty word with a cleaner one." It read smooth and there was no loss of interest for all that there is no sex or swearing. There is a bit of violence that mostly happens off screen, though we're given details of some of the fairly graphic results. I'd probably call it PG17, due solely to the two or three instances of violence.