Only hassle with different tunings is if you're trying to follow someone else's chords, or they are trying to follow yours.

The particular relevance of tunings like DADGAD to Gaelic music is it fits well with tunes which miss out the notes that would define it as major or minor, which is a bit hard to do with chords when you're playing standard tuning. The same reason Irish Bouzouki tend to be tuned GDAD or ADAD, instead of GDAE like a mandolin.

Once again, anyone got a link to a sensible DADGAD site? If it's getting under threat from the fashion cops, it's time I got around to studying it.