As a consumer of old style, luxurious satin products, I can tell you that sateen is the "new and improved" satin -- not! Just another way that American companies are cheapening the old, beautiful fabrics that we used to be able to buy.
Sateen is a notorious snagger and looks terrible after just a few wears. Don't be fooled. Real satin is usually silk or cotton and does not snag easily. I had a satin robe years ago that I wore for over a decade.
What really makes me angry about sateen are the declarations by the companies that this is actually the better product. It's not. They are just trying to persuade us that the cheaper fabrics are just as good as the old.
I'm having a hard time finding real satin, but I refuse to waste my money on sateen.