I grow a lot of historic Irises because some came with the house when I bought it and some were given to me by neighbors when I was originally trying to fill the garden and didn't have much money.
I use them mainly as "place-savers." When I need room for new roses or other plants, I just dig up a lot of the historic Irises.
I'll never get rid of all of them, however, because they're much more fragrant than any of the newer ones I have and almost all of them rebloom.
The foliage doesn't look any worse in the summer. If anything, Sue and I noticed this summer that the foliage on the historics looked better than the others after the Irises had stopped blooming, and although the historic ones aren't ruffled, the blooms are just as big as the blooms on the newer Irises.
There are about five different types of historic Irises in this photo, and the best thing is that they all have completely different fragrances. My favorite is one that smells just like chocolate mixed with mint.