I found this book quite unconvincing, which was a bit sad to me, since I am a polytheist and therefore was predisposed to believe him. However, I had a few issues with his main line of reasoning, and writing style.
He would go into great detail about things, like defining "the universe" and then other things that could have used more in depth discussion were throwaways. For example, "Thus, we are not really in a position to say it is unlikely that disembodied minds would acquire information by intuition. Perhaps our experience of proprioception can function as an analogue of what such awareness would be like. Finally, it seems the consensus..." Why is this comment about proprioception a throwaway? Many people don't know the definition of proprioception. I do, and I don't see what analogy he's making at all.
Later on, there's a whole discussion about minds and whether the gods can have them because the brain evolved, and the implication seems to be that gods can have minds because they didn't evolve. But whether or not they evolved and how their not evolving means they exist isn't really clear.
Then there was this whole section on goodness, and I just didn't understand why arguing for an all-good deity had anything to do with arguing for the existence of any deity.
I did appreciate the argument that it makes sense for gods to exist because there's no reason not to believe all the people who have said they've experienced them.
However, the language style was off-putting, and the book could have used a few more revisions and refinements. For people looking for a good book on this subject, I much more suggest "A World Full of Gods" by John Michael Greer, which is quoted in this book. It's much more readable and convincing.