As a personal observation only, I agree with the standing of the progressive radio show hosts. They may be unfamiliar to many here because progressive radio hasn't been around for long and their audience numbers may be a reflection of that. (These people are all well known on the speaking circuit.)
Schultz does an excellent job imo of keeping the show open to opposing viewpoints and he often has conservative guest speakers. For that reason I prefer his program over any others.
Miller is an absolute kick to listen to (think Molly Ivans) but she is less open to dissenting opinion.
I have only listened to Rhodes a few times so I can't speak to how open she is to opposing viewpoints. I just find her too obnoxious to listen to.
Roachboy, thank you for the interesting observation of Limbaugh creating an appearance of overall agreement to his stances. I do recall his audience was called "ditto heads" and they seemed pleased by it. It seems somewhat similar to Reagan's invention of the "moral majority." Why would someone wish to identify themselves as the "immoral minority?"