The drug story is fascinating and sounds well researched, but it is sometimes hard to keep up with all of the people in audio form. If I were reading it, I would probably flip back and forth to remind myself of people.
I did not care for the voices to indicate different speakers although the Sam Nunn accent was pretty good. I am a bit of a nitpicker on pronunciation, and there were a couple of issues--Lawton Chiles pronounced as Chill-ays and the Medellin cartel pronounced almost as medallion.
Otherwise, I liked the narration--appropriate inflection and easy to follow.