My YAMAHA twelver currently has only 6 stings rigged on it, which suits my primitive fingerpicking style just fine as they are spaced more like a classical.
When I did have it fully wired, I liked to run it a step low like rangeroger, and capo it up in the unlikely event that any normal picker would want to make music with me. Another rationalle for doing this is about 100 pounds less tension on the neck; 12-stringers are notorious for warping necks over time, and since it took me the better part of a day to tune her up (they are not nearly as forgiving of itty bitty tuning imperfections as are 6's) I was not inclined to de-tune whenever I was not going to be playing it for more than a day. The YAMAHA is built like a Frigate of the line, but I don't want to push our luck.
One of my favorite tunes on the 12'er is "The Wreck Of The Edmund Fitzgerald" by Gordon Lightfoot; it is in a minor key, as are many nautical tunes, and those wild harmonics can make your hair stand on end and virtually feel "The Witch of November"'s icy carress.
My version (Warner Bros. Pub.) uses Asus2, A11, Dsus4, D, Em and the occasional G. BRRrrrrrrr!!!