Community treatment. I've played several MMOs, and I learned a long time ago, my female characters are generally treated better than my male characters. People are more likely to pass on loot, stop and explain a fight I am unfamiliar with, run content they don't need just to be helpful.
I'll even go as far as saying that I don't believe it has to be sexual in nature. Even decent folk do it, real life women sticking up for their "fellow woman" and mature, well-behaved men that have just been brought up to be more of a gentleman and treat ladies with respect. Just noticeable advantages to playing as a female.
With SWTOR, I make a point that whatever characters are not female definately use a female companion. In either case, however, covering myself from head to toe in Clone Trooper armor really seems to create a generally Gender Neutral appearance. Needing an outfit that looks decidedly female, the loungewear and slave outfits are some of the easier to obtain Adaptables that do not cover the body head to toe.
That being said, I personally don't use the slave armor at this point. My Trooper is stuck wearing his set for the set bonus, and I've got Dorne using the Clandestine Officer suit from the Cartel Market. It's just way too tempting to have the Imperial Defector companion wearing the Imperial uniform.
Which is odd, when you consider most forum posters in the MMO community assume every poster is a guy.