Sound better using Major 7th chords and minor 7th chords

we can Sound better using Major 7th chords and minor 7th chords in our chord progressions. we achieve this by substituting our basic major triad with their corresponding major 7th chords and substituting our basic minor triads with minor 7th chords. Major 7th chords have the formula 1 3 5 7 or R 4 3 4. Minor 7th chords have the formula 1 b3 5 b7 or R 3 4 3