Now, I'm not saying that this is exactly a case of the movie/show being outright better than the book. While it's happened, with The Leftovers I think it's that neither one is very good, but only the TV show has more time to convince me that it can be better.
The main problem with this novel is that I didn't care about any of the main/POV characters. Every one of them was either boring, maddening, or both - and any growth and/or change that could have helped them seem more sympathetic simply never happens. Two characters in particular who are maddening from beginning to end are Tom Garvey and Nora Durst; the former due to his obsession with the shallow, boring Christine, and the latter because we're apparently supposed to believe that her dying her hair is a life-changing moment.
I will admit that part of me was hoping Perrotta would give some information about why his version of the Rapture happened, though I wasn't surprised or even overly disappointed that he didn't do so. The problem really isn't that he doesn't reveal the reasoning behind it (or really, anything about it at all) - it's that nothing really happens. At all. There is no climax, there is no character development, and there's really not much story development.
That said, this was a quick and easy read. Overall it wasn't boring while I was reading it, but simply so disappointing at the end that I wish I hadn't bothered (if any of that makes sense)...and at the very least it did make me appreciate the TV show a bit more. 1.5/5 stars.