I have bulldozed many instruments, large and small, 1850's and much later, into some form of unequal temperament (usually Thomas Young's, as described by Charles Padgham) with never less than startling results and absolutely no loss of functionality:   1) The difference in tone is clearly discernable to the layman and manifests itself with greater clarity and travel, greater perceived volume, and much less shrillness   2) Extended mutations are generally more useable   3) Tierce mixture