Had a 12-string since age 19 after I emigrated from the UK to Australia, and never been without one since. There's something about those shimmering overtones that completely satisfies MY musical soul. Never play with picks - have learned to get the most out of it with fingertips (don't use my nails). Managed to record a 24 track CD ("EKO12") containing bluegrass instrumentals, a few songs and some classicals, just to show what a 12-string can do. Still have my original EKO (it would break my heart to part with it) but recently also bought a new Takamine 12 with pickup for a new CD of original songs.
The story on everything can be found on www.clancys.com.au/music/music.html
PS. The guy who said a capo puts him out of tune ... probably capo pressing the strings too hard ... try a SHUBB capo (use the 12-string version which has a longer bar)... it provides an infinite range for clamping pressure ... adjust it JUST enough to stop the strings buzzing.