What a small folk world! I just started learning dulcimer with Lorraine about two months ago. She convinced all of us in her class to have our dulcimers reconfigured to fit four equidistant strings. I believe she favors the style because, to echo what Chuck was saying, it lends to the versatility of the instrument. It's music - there's no one "right" way of playing.
I wonder how many other players there are scattered throughout the world who play with 4 equally spaced strings because it was Lorraine who taught them...
I feel fortunate to be living in Boston where there is such a vibrant folk community. I'm still young (relatively young...) and have so much to learn, and it's wonderful to have so many supportive teachers around.