Soft and silky, as the name suggests, sateen feels luxuriously smooth and is often used in high-quality bed linens.
Sateen feels softer than percale because of the way it's woven. Instead of the classic "basket" type weave, you get with percale - where one thread is woven above and under consecutive weft yarns, the thread is carried over several weft yarns at a time - perhaps four - and then under one weft yarn. This creates a smoother feeling as the woven thread is interrupted by the weft yarn less often.
Sateen feels indulgent but needs to be treated with a bit more care than a percale fabric due to the floating yarns in the weave which may catch.