I can't talk from experience but I've always wanted to record a harp... but its obviously very different than most orchestral stringed instruments...
The sound radiates in all directions at once, not just from the body like with a cello.
So I would suggest medium distance micing that lets the sound develop into a cohesive whole in the room.
You will probably have to play with mics and positioning...
XY or spaced pair of omnis would be a good start... have fun.
