The method is especially well suited for smoothly modeled, rounded forms, such as young women's bodies.
It is well to know how to paint in more than one way. Some subjects are best treated one way, while others are most suitably depicted with a different approach. And of course it is desirable that there be discernible differences from one artist to the next.
There is yet another method that does not seem to have entered this discussion, and that is the method of underpainting the flesh areas of youthful, light-complected people with brighter (i.e., higher chroma) opaque colors, and then overpainting with opaque and semiopaque passages of greys or greyer colors, allowing the warmer underlying colors to show through from below to create the final effect as a complex optical phenomenon much like that created in real human flesh. This method was used by William Bouguereau to its best effect, but it dates back at least as far as François Boucher. It is mentioned in Daniel Burleigh Parkhurst's book, The Painter in Oil, though he does not go into great detail.
The direct-in-full-color method allows a much wider range of possible effects with the many pigments that are available to painters of today than was the case in previous centuries, when there were fewer reliable colors to work with. Formerly, artists were compelled to exploit every tendency of every pigment, including its opacity or transparence, to get the most out of a limited palette. There is still something to be gained from knowing how to do things the way they were done long ago, as there are subtleties in optical effects that are only possible through underpainting, scumbling, glazing and opaque painting systematically, all in the same picture, which cannot be duplicated in direct painting, even with today's expanded palette.
Virgil Elliott