What you'll note visually is that the crispness of the reflection from your paint will have less of a frosted glass look. But it's marginal. It is more of a paint health thing.
You will see the dirty it pulls out of the paint on the clay, but you may not notice the paint surface looking any different.
I like clay magic. But I"m tempted to use Mother's next time since it's a lighter color and I'd be able to see contaminants better.
It's odd, even though the dirt around here is red, the contaminants in my paint that I get out are gray. My ceramic brake pads hardly dust at all, but who knows. I know this year it'll get some red paint overspray off the car. I can feel it on the paint.