Helfand and Bierut are smart, well spoken and on top of design. I always learn something interesting. The show notes at the DO website are thorough and provide links to the designs, essays, history, objects, etc. discussed in each show. As another reviewer mentioned, Helfand has a tendency to talk over Bierut, but he's too nice to say, "Let me finish my &*%#ing thought!" His graciousness makes it all work, and Helfand is brilliant so she naturally has a lot to say. They'll work out that flow. The show is one of my favorite podcasts.
(I felt compelled to come back six months later to say they worked this out! A fantastic podcast.)