I can't believe I haven't reviewed Gaucho yet! The food is amazing, especially the sauces. I normally don't eat beef, but I do here, because it's so good. The menu is very reasonably priced for the quality and quantity you get, and it's not a concept that you see in every city (at least I don't know of any in Portland yet). I always take out of town guests here as a starting point in our food crawl/tour of Pittsburgh.
I try to come at off hours or order ahead for pick up. I stick to the steak or Rosemary braised beef sandwich. I've had the fish and chor y pan, but wasn't too impressed. Beef is definitely the star here.