An SC lens lets a little bit of veiling flare into the shadows. So you sometimes get the illusion of more shadow detail. It can occasionally push an object in shadow up a little in level so you see a vague hint of it. But mostly it's just raising the "floor" slightly, and that can make a picture look better in some eyes. It can also make things look a bit muddy or more grainy.
When Leica came out with the APO 90 Summicron ASPH, they devoted some ink to the fact that the shadows are blacker because of less veiling flare, and that this is good! 🙂
There has been some reaction against the latest Leica lenses as being "so well coated that they have no character." So that camera companies are making special edition SC lenses and marketing them to those that don't like the clinical modern look. The Japanese in particular are going for these SC lenses,
Marketing can always spin straw into fool's gold. The question is, do you actually like the look? If you do, go for it. If not. . .
--Peter