If one examines a Bouguereau painting, there are a lot of details left out. On the other hand, one is not concious of the missing details as one would be with some coarser styles.
Yeah, Bouguereau's work is not exactly coarse. But trying to put in too much detail is a fairly common error of beginners. Although modern photorealism does seem to specialize in it. Imitating photography seems like something of a pointless artform to me...although perhaps the pointlessness is the point!
My opinion is that relying on "optical aids" is harmful to the drawing skills of the artist if they are used too much...artists need to draw a lot to stay "in training" just as athletes need to work out regularly for the same reason. You hear that heard so often that even many of the guys who do abstract are believers in drawing pretty much daily.
I happen to really like that picture in post 134, been a favorite for awhile. I wouldn't mind seeing it in person.