I use the open D frequently .. in fact it forms the basis for my reconfigured Backpacker - (that is I use a Nashville tuning, then a D Major). It's lottsa fun!

D Major is good for slide, and for folk/blues tunes. You can get some interesting chord voicings, and have nice options moving up the neck. I've written a few songs using Open D. And capoing is OK, as others have said, but you'll find your neck inconsistenies are more sensitive to the capoing when open tuned (though your Larrivee will likely be darn near perfect). The decreased string tension makes it easier to overstrech the string using the capo, also - so it may have some impact.

Anyway - good thread moonchild! How's the new Larrivee settling in?