Let me preface my criticism with the comment that I love the SGU so much that, if I detect that Steve sounds a little testy, I worry that he will can the whole thing and stop producing one of the highlights of my week, the SGU podcast.
Let me also say that the add that the addition of Cara has produced a panelist who can match wits with Steve and added a bit more scientific rigour to the general discussion, as well as adding another likeable personality to what is already a great mix of characters.
My chief beef is this. Speaking for myself, I listen to this podcast for the banter; the interactions between a bunch of smart, thoughtful people as they chew the fat on the latest events in the sceptical world.
I do not listen to learn the meaning and derivations of a word like impedance. If I'm at all interested, I'll look up Wikipedia. Nor to I really want to know the specific name for a type of fallacy, another topic which occupied some time in this week's podcast. It is important to recognise fallacious arguments. Not so important to be able to specifically name it. If people are really interested, again, Wikipedia is your friend there.
I would end the 'whats the word' segment ('jackass of the week' was more interesting and topical). I would ask the panelists to remember that it's the dynamic between them that makes the podcast interesting, funny and worth coming back to. Long discussions by one panelist about the meaning of words and what particular name should be given to a poor argument are not those things.
I hope I haven't trodden on anyone's toes here. The SGU changes lives. Keep up the good work.