So I usually smoke extracts nowadays but I tried delta 8 flower and extract. I can get high on one joint of delta 9 (above 25%). One joint of 15% delta 8 did absolutely nothing for me. 86% delta 8 extract had me feeling good at about 8 heavy hits. I'd argue it's about 30% the effectiveness of delta 9 and less psychoactive. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.