Yes, I do. I know some in here are huge mlb.tv fans and I'm not knocking that, but the main reason I get Gameday Audio is to listen to Cubs games at work. I can't exactly watch games at work so the audio is just fine. Plus when I'm at home the Cubs games are on tv for pretty much every game except for a few broadcasts so I have no need to watch them on my computer anyway. Plus the $14.99 is a bargain.
If I was a fan of a different team like say Philadelphia and I was living in California, then mlb.tv might be nice to have in order to watch some games at home, but for what I need its just not worth it.