I'll admit that I've not exactly listened to a number of podcasts about birds, so I couldn't tell you how this compares with any others that might exist. What I can say is that this is an incredibly soothing podcast to listen to. I enjoy learning tidbits about the birds and their songs, too, but really truly find it to be incredibly nice to have on about the house.
You know those nature programs that feature the sounds of nature, with a soft-spoken narrator letting you know in hushed tones just what you're observing? This is the podcast, birdsong-specific version of that, and I love it.