I was in Pittsburgh for business and visited Gaucho twice for dinner, despite the 30-45 minute wait to get it. The flavor here is incredible. If you have a problem with waiting in line (or you're that person that will endure but complain about the line to everyone waiting), don't kill the vibe and head down to McDonald's... You can see it from the line.
Also, it's BYOB. So grab a bottle of wine on your way. Or two, one for dinner, one for the line.