Tradio works because the calls are often short but you get a ton of them. Beats the hell out of Sal and Richard doing long "elaborate" bits and "characters" (although I love Ethel!) with stupid people. It's also great because of the pranked tradio talent. Frankly, the reaction is almost always funnier than Sal and Richard themselves. Their best pranks tend to the ones where they use tapes, but that probably wouldn't work well with Tradio. They found a good thing and shouldn't let it go.
I liked the first few, but as always I'm sure they're heavily edited/manipulated afterwards. And then Richard and Sal run the concept into the ground with tons of subpar calls, which end up diluting the two or three that are really funny.
I do admit that the one where they proclaim Jon Hein as the "Blowjob King of Michigan State" is pretty funny.