I had Dusky Challenger for about 8 years in a sunny area. The flowers were huge, lightly ruffled, and magnificent. Then during years of neglect (during my own chronic illness) I lost it, due to borers or rot. But I knew I had to have it again. A couple of years ago I bought it again, but planted in a too-shady area. There its blooms were disappointingly small. But having seen it before in all its huge glory, I knew what to do. I moved it to a very sunny location again, and this year again it was wonderful.
So what I am saying is that if DC is turning out less than you expected, try it in full sun, and it will reward you.
Having said that, I'm awfully glad that you have it, and I, too, am interested in seeing some of these others in person, particularly, Magnificent Masterpiece.