For the classical perspective ask this question on Maestronet, http://fingerboard.maestronet.com/cgi-bin/Ultimate.cgi

For the old time and bluegrass perspective ask this question on Fiddle-L, http://www-openmap.bbn.com/users/gkeith/fiddles/fiddle-l.html

All my friends play old time fiddle rather than classical violin. They change tunings way more than classical violinists and for them convenience of multiple fine tuners outweighs their tonal impact.