The Shuffles are the best at audio podcasts, imo.
Solely based on their ease of control input.
I can much more easily go back and forth from song to song, or ff/rew with a shuffle.
The control is small, good tactile feedback.
The iPod touch/iPhone is the worst. No tactile feedback, you almost have to use two hands and at least use your EYES to see controls.
Yet, dumbest thing is, the shuffle cannot automatically update podcasts.
I use a Nano as a happy medium. But still, the controls suck compared to the (original stick) shuffle.