I've got an Ovation and a Martin. The Ovation is horrible when mic'd, but good for finger pickin style when plugged in. I've had fair results if I mic at the 12th fret and blend with the p/u when recording.
I don't like the Martin plugged in at all. Haven't had a chance to record it with a mic, but I think it will sound beautiful. Listening to that thing when I play is relaxing.
Cheers,