I'm more than four hours into this eleven-hour novel, which, in the audiobook version, is a full cast production.
When "Sleeping Giants" was presented in the same way, I'd lost patience with it by the four-hour mark.
This time, I'm enjoying myself.
I put the difference down to the quality of the writing - the characterisation and the emotion in the dialogue / first-person reports are excellent - I found the report on a Marine SNAFU assault quite moving for example.
There is also a nice balance between a more personal relationship between the two teen protagonists and the more role-driven interactions between the captains of the military and civilian scientific ship.
I find it difficult to listen for more than an hour at a time, but I think that has more to do with the quiet desperation of the story than to the format.