David,
I used to use DeChaunac in a mixed red blend of FA hybrids, and it worked well, if I aged it about three years. The other grapes were Chambourcin, Baco and Chelois. By itself, or too young, DeChaunac is something of an acquired taste. Complimenting the others, however, it made a positive contribution to their shortcomings.
I think I originally planted DeChaunac because of its reliability of production, not because it was especially good in and of itself. Other than blending and/or extended aging, Bill's suggestion to graft over to another variety sounds good
BTW, I have replaced my DeChaunac and Baco with NY73, both in the field and in the blended red.