I found it to be very entertaining, but I would like to know just how much of a grain of salt to take the information with.
As a popular podcaster, Dan Carlin comes up a lot in this subreddit. So much, in fact, he has his own chapter in the FAQ. It doesn't specifically answer about Wrath of the Khans (hopefully someone does provide an answer), but it will give you a general idea of the balance between "information" and "entertainment" he provides.