I lost Shin Tso to late frosts. That one came out of dormancy way too early for my climate (7a). Sham Dudu is the only one that already fruited for me. It is a true morus nigra cultivar. I do have more morus nigra growing but those are still young grafts and didn’t fruit either. So I do not have much experience with the taste of morus nigra, besides Sham Dudu. From what I read from others Sham Dudu seems to taste like your typical morus nigra. Unripe fruits (red stage) are quite acid tasting. When fully ripe (black stage) that changes to a very nice sweet-sour balance. Plus the fruit has a spicy taste to it, peppery I’d say. I only detect that in ripe fruit. I really like the fruit from Sham Dudu.