Sweet versus Tart Blackberries?

Hi to all,

If there are any real fans of blackberries out there, could you describe any varieties you have tasted as being decidedly (1) Sweet  (2) Tart  (3) Neutral or complex.  Many thanks.

I have grown a few sweet varieties over the years but my favorite and current type is the Prime-ark freedom.
they are very large, very sweet and very productive. Being primo-cane, they put out a massive cop over about a month in mid spring. ( on new growth). Then a heavier but slightly smaller berries in late summer to frost.  I planted 6 bushes.  This year I got about a gallon of berries every other day for several weeks.  They have now started flowering on the lateral branches for my later crop.  They are erect plants very tall and thornless.
 I have had brix readings of 15 on these blackberries. They make great wine, syrup and jelly .  I highly recommend them

Thanks Ralph, I have to look into that one.