The advantage I have seen many women bring to their first lesson, though, is that they don't typically fall victim to machismo. IE, they actually listen to instructors, and don't feel they have something to prove - instead, they have something to learn.
I disagree with this one, too.
What I have seen is that most men and most women make excellent students. I don't see a whole lot of these testosterone-blinded men people go on about! Most of the guys I've worked with over the years have worked hard to learn what the instructors had to offer.
A few men are poor students, and a few women women are poor students. The percentage of poor students seems to be about the same between the sexes. It's not common, but it does happen.
Here's the kicker: culturally, women are trained to hide it better when they shut you out. So an instructor who isn't looking for it often misses the attitude shift that says she isn't listening. She starts out pleasant even if someone twisted her arm to get her into class, and she keeps right on being pleasant even if she decides you're full of crap. That doesn't mean she's listening, and it sure doesn't make her a good student; it just makes the instructor less likely to notice the problem.