John have you tried natahala, itsaul, bababerry and dorman red?

Yes to 'Dorman Red', no to all the others. I keep looking for 'Nantahala' but it seems to only be offered in the mountains here in NC. I took me five years to track down some 'Mandarin'.

i got nantahala from Indiana berry I’m not far from the piedmont’s myself in north Georgia elevation 1090 ft. We’ll see how they do. Do you like dorman red? Never heard of mandarin

Dorman Red was good and I think it lasted two years. Mandarin is an old variety developed for this area. It has a lot of Wineberry blood in it but full red raspberry flavor. Its leaves are a little rounder and the fruit is kinda round also. Next to impossible to propagate, none of the usual tricks work. No one sells them anymore. Out of a dozen attempts I can maybe get 5 to root and out of those maybe 1 will be alive the following year. They do spread by runner but only after being well established and I can only get one of those offsets to really thrive after potting it up. I also liked the fruit from Josephine and Polka, very tasty and large long fruit. One week of 100 degree weather wiped them out.

I'm not sure I'm hotter than the OP, but I'm in NW Arkansas (z7) and I have Jewel and a purple raspberry that I don't remember the name of just now. Bear in mind, I ordered 2 plants of each three years ago, and one of each died. The blackcap is trying to take over the yard, and I let it go quite a ways, so I have more than a dozen clumps now. I've been picking 1/2 cup a day every day for about a week. I'd say another week of that then done.

This year, the constant rains have somewhat got to the fruiting stems of the purple, they look sad, but new canes look good.