Alternate tunings are awesome. I hardly play in standard tuning anymore. They make life so much easier. It's only frustrating trying to figure out what tuning a song is in when you're trying to learn it. Usually the ridiculous chord shapes and movements give away the fact that it's in another tuning. Then you just have to try the typical ones and see which one makes it easiest.
I call it cheating, but I wish I would've gotten into them earlier in my playing career. They open up so many more song possibilities.
And why didn't you just learn the song in DADGAD? It's not that hard to tune to. That's usually my "standard" tuning these days since I can easily get to open-d or drop-d from there.