Female armor (in regards to soldiers with helmets) is designed a certain way to let people know "This is a female and not a really skinny dude". I think the issue stems from the fact that people go too far to prove that it's a woman and they end up designing armor that is impractical on the battlefield (every fantasy MMORPG ever) The fiction/realism behind the design should all be there behind the scenes (we don't really customize sports bras but they're there doing their job), so what really needs attention are [subtle] visual cues. How can we say "This is a woman in armor and not a man in armor" without making the design impractical? This is key. It has to look like real armor (male armor) but at the same time we have to be able to tell that it is a woman. Otherwise, what's the point in switching avatar gender? And I agree that this was done really well in Reach.