Welcome to ECN Phil,
I'm surprised that no one has mentioned "Height of a Hammer" for receptacles. (if working with someone else you'd have to "synchronize" Hammers of course). This puts the receptacle at about 13" to the bottom.
I figure 48 to the center for switch boxes makes it's easier to sheetrock, and if the Tapers don't have an attitude it really doesn't affect them.
Bill
