I never learned much from Duolingo. It makes learning languages incredibly boring, and my eyes would glaze over every one of the dozens of times I had to match/construct some variance of "der junge trinkt die milsch." I learned more German just reading English translations of Rammstein lyrics. Anything by Pimsleur is still not very interesting, but at least it can hold my attention.
Anki is pretty awesome. I spent about 1000h learning Japanese with Anki so far. Together with Yomichan it's pretty much the ultimate learning tool, imho.
I learned more French from a day of trying to read Le Petit Prince in French, with the English translation beside, than I did from 3 months of Duolingo.
Rote learning just doesn't work that well for most people.
I find Memrise much more interesting and "powerful". It only shows you sentences and relies on your brain to know how the grammar works (a bit like how a child learns how to speak).