Appalachian Dulcimer Traditions-which edition?

I want to add some specific dulcimer history books to my growing library of Appalachian history/culture--I see that there are two editions (2002 and 2010) of Appalachian Dulcimer Traditions--has anyone looked over both (in addition to Mr. Smith himself since he is a FOTMD member)--are there signifcant differences or additions in the second (2010) edition?  I searched for a discussion on this but did not find one.  Any opinions welcome.  Thanks!