
I love Slipknot and am not sure what you mean by "kiddie" metal. Certainly simpler song structures than other metal, and the percussive focus is not for everyone, but kiddy? Errrrrrmmm... Don't know if I'd agree when I have kids. Lol
Stone Sour's hits have usually been either ballads like "Bother" (Spider-Man 2002 soundtrack), "Tired" (House of Gold and Bones, either Part I or II), "Through Glass" (Come What (Ever) May) or hard rock tracks like "Gone Sovereign/Absolute Zero" (House of Gold and Bones Part I). Heaviest single they have is "Get Inside," I think.
You've probably hard either "Through Glass" or "Bother" without realizing who it was. Maybe not.
It's odd to me how much more radio friendly Stone Sour can be, yet Slipknot is the better seller by miles, perhaps because it stands out more than Stone Sour's moRe straightforward rock sound