I guess it's a personal thing, I don't really like Overlays at all. They're suited towards special applications of decals on surfaces such as displacements or around curves or at angles, while decals are useful for things on flat surfaces like posters on flat walls or trash decals on flat surfaces on the ground. They're limited in count in your maps and they also have a face limit to be applied to, and they generally break my compiles which is why I try to avoid them.