I notice in reading so many of these works that female characters sometimes seem only nominally women; change the gender of pronouns from "she" to "he" and there would be little real difference.
Which is interesting since some women complain that they don't see enough representation of their sex in speculative fiction. I remember reading one forum thread where a woman disliked how in the original Star Wars trilogy, the only female characters were Princess Leia and some sexy alien dancers. Why weren't there any female tie fighter pilots?
Personally, I never really understood the issue. I don't get offended if I don't see a woman in the story. I don't even mind the oversexed females, assuming that they actually do something, rather than just being eye candy.
To me, the most important aspects of a character are a) they act on something (none of this sitting around and boo-whooing) b) they use their brain (YA has given rise to the "dumb as fuck" characters), and c) they have a personality and a history.
Nothing that I listed has anything to do with what the character has between their legs. The character should feel right at home in the story, rather than be shoe-horned in because the writer felt like he/she had a quota to keep up.
For me, I write whatever character walks onto the set, whether they be male or female, straight or gay. I do give more careful attention to nationality, because if I set a story in medieval Japan, the main character probably shouldn't be white.
However, I thought about whether or not personalities are completely sexless. Because I like to think that a story about a woman character is more than her having a vagina, that her womaness shows through in her personality.
A nominal woman sounds uninteresting to me (as would a nominal male), like they're stock characters or something. I mean if you're going to write a character, then write a character. Not some walking generality. Because a bland character usually means a bland story, and I don't finish bland stories.
And thinking back to some of my favorite stories, I've noticed the characters feel distinctly male or female. (Unfortunately, I haven't encountered much in the way of transgendered characters.) The stories weren't even about gender issues; it was just the way the character talked or behaved--and not in a stereotypical fashion, but like real people.
So yes, I believe a character's sex is an important influence on personality. You might argue that the personality of a man and the personality of a woman are not that different, and whatever differences that exist are because of gender traits that society has placed on men and women. That's a tough one to say, especially when we're still trying to figure what is "man" and what is "woman" outside of gender roles. But I feel the difference has to be deeper than our genitalia. We do after all manufacture different amounts of hormones which must play a role.
(And if you haven't guessed the title, it's a rift on "What's in a name?")