I grow both species of Doryanthes in my garden: Gymea Lily (D. excelsa) and Palmer's Spear Lily (D. palmeri). Neither has flowered for me yet, but even their large and imposing foliage is reward enough.
It is also wonderful how the leaves closely mimic those of some of my Furcraea and Beschorneria, particularly Furcraea foetida, despite being quite separate both genetically and geographically. I enjoy repetition in garden design better when it is pseudo-repetition.
My garden is in USDA Zone 9b, and I've seen no frost damage on either Doryanthes, though it has happened to my Furcraea foetida.