The Qd6 scandinavian is not only playable, it's pretty good! It's steadily becoming part of my repertoire. I only have one game playing it on here and it's a lost, but to a better player which doesn't mean much. Here's a link to a Roman's lab, the comments are exaggerated but interesting (I've seen it, it's alright) The main advantage of the scandinavian is that white is pretty much forced to get into it without giving away an advantage (except if he transposes to a Panov-Botvinnik attack), so you get a fully playable opening with a twentieth of the effort that you need to play the other openings against e4.
However, you need to play c6 to prevent the threats to the queen with the knight, the old move was a6, but it was shown unsound vs a kingside fianchetto. Castling kingside is also sounder.