From your descriptions, I think I'll stick with Medium. (Full disclosure: NewsBreak turned me down). I'm not a big fan of content mills, which NewsBreak appears to be, or gimmickry, which seems to be the case with Vocal Media.

At the same time, I don't put in enough effort with Medium to be a big moneymaker, but I like the clean format and the company I keep here.

I appreciate your doing this, though. Writers need to know about possible choices, and they can decide from there.