Musing has a team of moderators who review the questions and answers and upvote the best ones. There is even a set of curation guidelines, here:

https://docs.google.com/document/d/1WKYGhdPhLKNHytsxAPPQiXyv5UBY6nUKM8IhG5PUgfA/edit

From my experience over the last couple of months, the system works well. Better answers are more likely to get better upvotes. 

And while no system can be perfect, overall I think that it's one of the best systems I've seen on Steem dApps for separating out quality (Utopian is also very good at this). It's certainly better than any automated system since they always end up being gamed. I think that these moderated systems are really good for Steem, since the original idea is to find the best content on the web. For me, this feels like a big step forwards.