I taught newswriting as an adjunct in the journalism department of a state university for a couple of years, and Barzun's "Simple and Direct" was on a list of books and essays I strongly recommended to all my students.
I used to work as a radio news and documentary producer and news director and I found Barzun's prescriptions on prose style a reliable guide for editng my own work and others as well.
Barzun's approach can be a bit irritating at first because he tends to be fairly prissy about style, but if you can get past that, you begin to perceive the prissiness as a tight focus on precision of the type that is lacking in much modern prose writing.
His main rule is one I paraphrased at the first meeting of every newswriting class...that there are only two reasons for producing bad writing; either you don't know what you're writing about, or you don't know how to write about it.
I lost my copy of Barzun years ago. I think one of my students walked off with it. If so, I hope he or she is using it. I'm glad to know it's still available.