Who has the edge in RSL-LA Galaxy semifinal second leg?

A brief storm erupted on Twitter in the aftermath of the 0-0 1st leg draw between the LA Galaxy and Real Salt Lake.  Sports Illustrated writer Grant Wahl started it off by suggesting that LA holds the edge by playing at home for the 2nd leg.  That was quickly countered by the likes of Alexi Lalas and others stating that it was RSL that actually held a slight advantage.  So who is right?

Here's some stats to break things down.

• LA / RSL have now played 33 games against each other (regular season & playoff).
• LA has won 39.4% of the matches (13 games), and 55.6% of their home games.
• RSL has won 36.4% of the matches (12 games), and 40% of their home games.
• LA has won 20% of their away games (3 games).
• RSL has won 33.3% of their away games (6 games).
• 24.2% of the games have been a draw (8 games, 2 in LA, 6 in Sandy).
• The Nov. 11th game was the FIRST scoreless draw between both teams!

At first glance, LA holds an obvious edge by winning the majority of their home games vs RSL, but in this matchup the Away Goals tiebreaker reduces that advantage.  RSL only needs a win (6 times in LA) or a scoring draw (2 games in LA) to advance.

This gives RSL a 44.4% chance to move on, but LA retains a 55.6% home advantage.