I've researched most of these brands and more, and yet know one does a desktop system that you can stick a USB stick/SD card in full of podcasts and listen to them while you work.
The let-downs for them are that they:
1. don't remember last position if the machine is turned off, or power is otherwise lost
2. have no FF/RW within tracks, which you need for tracks that are 30-60 minutes long
3. tiny buttons or so vertically unstable that you have to hold them to operate them
4. No display to show track information
My cheap car stereo lets me do this, but honestly it seems there's nothing for the home that I can just toggle on and off when I walk into the kitchen. I don't want to have to plug in an iPod as that introduces more layers of complexity.