ganainm, I have tried out the tuning as you suggest and I can see some, but very little potential in it. The problem is due to the fact that the dissonant G string in DAGDAD is tuned an octave lower than the dissonant G in DADGAD consequently any upper fret use of this string for melodic effect (which every DADGAD guitarist does) is going to sound really low and drony.

My feeling is that the DADGAD tuning is so incredibly useful and has so much potential, why would you want to make life difficult for yourself by even bothering with DAGDAD, when you can do everything you want in DADGAD with so much more fluency?

Murray