It's a bit less, hm, cheerful than Firefly,

I totally don't mind a show more sombre in tone. I mean, one of my fave sci-fi shows set in space is Battlestar Galactica and that was downright depressing at times.

MUCH better at treating sexworkers.

Sadly Firefly set the bar so low on that score that it's not hard to believe but still very good to hear!