"Very enjoyable"
This was an entertaining audiobook, with a few key drawbacks that keep it from being 5 stars. First, as noted by many other reviewers, the narrator's female voices are pretty bad. They all come out sounding Southern. But I thought his male voices were well-distinguished, and the straight narration was good as well.
Secondly, the pacing of the story itself is a little strange. The entire first third is character introduction and buildup to the comet strike, then the second third is the strike and immediate aftermath, and the final section is the extended aftermath, including a kind of quick action climax that seems out of place compared to the general tone of suspense in the rest of the book. I felt the third part was rushed, while the first was too drawn out. That said, the writing is excellent throughout, and the various storylines intertwine in some unexpected ways. I put it in the same category as a fun summer action movie that turned out to be better than you expected.