I'm a heavy consumer of audiobooks. I have a lot of time during an average day where I can listen while doing something else that doesn't require a lot of attention.
My main complaint is that, particularly with older titles, the audio quality is often very poor. For that matter, so are some of the readers. My hearing isn't so great any more, so properly enunciated English is sort of important.
The ones that are good tend to be very, very good, though. I've listened through a few several times, just because it was a pleasure listening to the reader.