I've really enjoyed the odd essay/opinion piece and Teaching Company lecture series by McWhorter. I've heard people rave about the podcast, so I gave it a go.
I felt badly for the fellow, however, after listening to about half an episode of the podcast. It seemed worse than AM talk radio in terms of commercials, which left me with the impression that the guy really needed the money.
That was some time ago, though. I just scanned a recent episode and it looks like there are only four commercial breaks in 40 minutes which is not quite as excessive as I recollected. If that's not something that bothers you, give it a listen.