I certainly prefer the major notated when differentiating between the major 7 and dominant 7 chords, and I also prefer the minor notated simply because both major and minor chords of the same root may appear in tune accompaniament, major being the "default". One assumes a minor chord based on the second and third intervals of a major scale but it's not always the case (Hey Good Looking, I think). But, the third could be dominant 7 too, particularly when leading to the relative minor, could it not?

I've never liked the Nashville system, I admit my bias, but I like "shorthand" methods a lot.

Sorry, I'm not at my usual computer, and don't have my glasses. Hope that made sense.

Peace, Mooh.