The downside of Podcaster for me is lack of integration. I just checked their latest version, and it still seems to silo the podcasts in it's own storage area instead of using the iPod area (not sure if it even can). It's also lacking AirPlay support, so I can't play a podcast on my home audio setup easily. With my short commute these days, I've been more dependent on the ability to play a podcast at home for a bit before heading out the door, and the iTunes syncing including playback position makes this convenient.

I do like the app concept though, as it's similar to the Google Listen that I used on the Captivate.