Well, I'm done with Duolingo (at least for Dutch) -- I got through the whole Dutch course and then went back and got everything refreshed to all golden at the same time and honestly? Duolingo _does_ help with language learning, but there are some serious flaws in there. And having re-activated Babbel for a month, I will just straight up say that you pay for what you get. Babbel's speakers are _way_ _way_ better. I think I would have cared more if I had not been working with an actual speaker of the language.
In any event, rather than going through the main line of the beginner's course, I'm poking around at some grammar areas that I find persistently confusing. Babbel is not nearly as powerfully gamified as Duolingo, so there's a serious motivational deficit (also, no leaderboard that I can detect). This is a big deal -- the language (learning tool) you are motivated to try to use every single day probably has an advantage over the language (learning tool) you ignore for months at a time, even if it is in other measurable ways ... worse.