Thinking back on that distant conversation with my host sister:
As an American, I had pretty much a knee-jerk reaction against authoritarianism of any sort, believing without any particular examination that democracy was clearly the best system. At the time, I saw no reason to fight with my host sister's assessment--better to listen and try to understand how people feel than interject my own feelings into a conversation about (and within) a culture that is not my own.
But I'll never forget that particular choice of words, "Superbuenas." During my stay, I'd heard the line about how when Franco was alive, at least the trains ran on time. And maybe they did. But during his rule, Franco imprisoned and executed hundreds of thousands of people. So I'm guessing there were and remain a whole lot of people who wouldn't have minded that the train schedule be bit less precise, and really didn't find things superbuenas at all.