Rob points out some good and bad applications of EIFS.
EIFS was originally developed for—and intended to be used on—vertical exterior walls. It is not a roofing material, nor is it a below-grade insulation or waterproofing material. It is also not well suited to large sloped surfaces such as windowsills, especially when the slope is shallow. While it’s true that EIFS can be applied to such surfaces, and does occasionally fare well, it’s not really what EIFS is for.
But what about upside-down surfaces such as soffits and ceilings? EIFS is used this way all the time.