Maybe 3 stars? It wasn't bad, but it telegraphed most events way in advance, so that I spent most of my time waiting for things to happen that I already knew were going to happen. Also, Scalzi's dialogue tag problem was really noticeable this time around. I don't know if it's just sinking into my consciousness more or if it really was more of an issue in this book than it was in the others by him that I've read.
Wil Wheaton's narration was similar. Not bad, but...okay. Very easy and enjoyable to listen to, but almost entirely "Wil Wheaton reading the book." Almost zero attempt at different voices for different characters. The only exception came near the end. He handled that voice well, even though it was probably exhausting.