Unfortunately you're comparing apples to oranges.
Google Analytics is web statistics, tracked via Javascript. Yes, you can track when a media file is downloaded, and it may be possible that Google Javascript can capture when Flash based players are loaded, but when a Flash based player downloads the file, Google Analytics will not have access to that download event. It should be able to track HTML5 audio/video downloads however.
Blubrry Media Statistics tracks media downloads specifically, from web page downloads, from Flash plays, and from feed syndication (Google Reader, iTunes, Podcast app on iPhone/iPad, Android podcatchers, etc..). This covers 100% of all media downloads, where-as Google Analytics is limited to only those from the web browser that are accessed directly.
Keep in mind that the typical podcast gets 60-80% of their podcast downloads just from Apple products (iTunes desktop, iPhone/iPad), Google Analytics never captures those downloads syndicated through your RSS feed.