I think Friesians are the dairy sheep of choice, but when I looked at pics of the Dorpers, I was real impressed with the size of their udders and the info provided says they have a real high milk fat %.
I'm getting a Dorper ewe in the spring myself, for this very reason. I really like the sound of the breed and hope to make a little cheese on occasion, as well as raise some lambs for market. Also make a good lawn mower for my orchard!
Docile, VERY easy keepers, very hardy, good mother's, and nonselective grazers, all true. I know they got good meat on 'em, but I aint never milked one or drunk any... I'll try it sometime and tell ya what I think!