Here wild blackberries are too sour and small for my tastes, plus they are thorny, so not an attractive resource for me, although my wife likes them. I prefer our thornless domesticated varieties.
We also have wild black rasps, they are sweeter and just taste better, but they are outnumbered by the blackberries by prob 5 to 1. We have two tame varieties, Bristol and MacBlack which should produce their first crop this year.