I really think they are alive!

I think my Agave perryi 'Super Hardy' have lived up to their name!
The big one looks absolutely undamaged -- no mushyness or anything:

The small one (a pup from the big one) isn't quite as happy, with a few mushy leaves, but the damage seems to be just on the outer portions of a couple leaves -- no signs that the center of the plant is rotting out.

I'm so thrilled! I didn't even give a special spot -- I put them in a relatively well-drained part of the garden, but no special rock garden treatment or anything. Who knows it they will prove to be reliably hardy over the long run here in zone 5 (unlike the rest of the country, we had a slightly milder than usual winter) but I think I could recommend them with confidence in zone 6. The sad news is that I no longer know of a source for it. I got mine from the always amazing Arrowhead Alpines but they don't list it in their catalog for this year. Luckily it seems to make pups pretty freely, so hopefully I'll be able to have lots of them soon. And you never know -- we you visit Arrowhead in person, they often have plants that didn't make it to the main catalog. If I can, I'm getting more.