Excellent review George.
I grew Takanotsume for the first time this year, and I'd say your description of its flavor was spot on.
It never occurred to me to try it on a sandwich. I'll have to give it a try.
I've grown the Takanotsume for the past four or five years [SIZE=12pt]primarily [/SIZE]as an ornamental, it's a great looking plant. The last few years I've dried the pods and flaked them for general semi-hot addition to recipes.
Here's a shot of a branch with half of the pods remaining.