For a lot of people, Superman is and has always been America's hero. He stands for what we believe is the best within us: limitless strength tempered by compassion, that can bear adversity and emerge stronger on the other side. He stands for what we all feel we would like to be able to stand for, when standing is hardest.
Sentiment: POSITIVE
You can see how he changed on the surface. But at the core of it all, I think Superman has remained the same - a character with incredible powers but almost superhuman humility and restraint.
The way you challenge Superman is by having things happen very, very quickly in different places and then asking, 'Who does he save first? What powers must he use to save each person or stop each disaster?' That's one of the ways you make him interesting beyond the thematic and moral issues that make Superman.