"not enough material for a book"
His point is important, but there's not enough original information for a book. Too much padding with example stories that don't add new info.
"Too much abridgement"
I'm a big fan of this series of books, but this abridged version just didn't have enough meat on it. I wish I'd bought the paperback instead.
"Great reader, classic story"
That's all you need to know.
"More about civil war than gold rush"
I bought this because I'm interested in the Gold Rush. Two hours of listening and we're still on minutae of California pre-civil war politics and transcontinental politics.
I doubt I'll finish.
"full of it"
I couldn't stand to listen to it, this man was so full of "it" and of himself.