Is this a brand new opening for you? If so, how likely do you think it is that you will gain a deep understanding of the typical middlegame and endgame structures in time?
You can memorize all the book lines perfectly, but once you reach that = or +/= position, you need to know what to do.
I play the Scandinavian pretty regularly (started with 3...Qd6, but switched to 3...Qa5). I dream about the day someone finally plays the book lines against me. This is not the opening to play if you're looking to gain the initiative ... if White plays simple moves that aren't even mentioned in books, Black still has to be careful, and it's rare that I get anything going in the middlegame.
That said, a lot of players have this irrational disrespect for the opening (they think that 3.Nc3 wins a tempo, when a glance at the position proves otherwise) and these types often take liberties in an attempt to crush the opening quickly. They will push all their kingside pawns, or sacrifice on f7/e6, or any of a number of things in order to "punish" you. My wins come in these games or in endgames, where my peers haven't put in as much work as I have.
If you want good chances to grab the initiative, though, 1...e5 or 1...c5 are, as always, the best choices.
I'm playing in a tournament that is coming up and was wondering if the Scandinavian defense is a good choice to play for a WIN. I'm thinking about playing the classical(Qa5) line.