David, Anne-Marie,
there is (at least) in my case a distinct difference in sensitivity on the operated vs the "native" portion of my tongue. Both portions received similar radiation dosages but the allograft side (aka franken-tongue) is a lot more sensitive to irritants (still).
The water color comparison is perfect, plus the the taste seems to fade (my case) a after a few seconds. Still, it is a lot better than it was just a few months ago.

M