I had several other daylilies that started with a "D" but I have noticed than the majority of the daylilies I have lost over the past two years have been dormants. It seems dormants have a very short life span in my garden.
Semi-dormants do better and Evergreens seem to be the direction I should go when choosing more daylilies.
I wanted to add that I was reluctant to post the statement above because I had developed the idea in my head that there was really not much validity to the almost "arbitrary" way the dormant, semi-dormant, and evergreen designations are arrived at. Still, thinking that the designations were almost meaningless in the actual growth patterns of the plants, I realized that when I lost a plant and looked for a common cause the only thing that stood out was the term "dormant". So I now think the terms have definite applicable uses for people in the deep south and far north, maybe not so much for a lot of people in between.