I bought the in-app purchase for Overcast and I’m linking to Marco’s post to support him because I enjoy the ATP podcast he runs along with Casey Liss and John Siracusa.
However, Overcast wasn’t a fit for me. I found the navigation to be awkward and the per-podcast playback settings nearly impossible to find (hint, click on the podcast logo on the left side of the player controls along the bottom of the screen to bring up the episode screen, then the playback settings for the podcast can be adjusted using the button/link in the bottom right corner). I’m sticking with Castro for now, but will be keeping an eye on Overcast.
I’m also not a huge fan of his approach to become an intermediary between the podcast providers and me. The Overcast service checks podcast feeds, and the Overcast client talks to the service – this is basically the model that Google Reader made popular for RSS feeds. I do understand how this can make checking for feeds more efficient on the client, but it introduces a single point of failure.