Personally I never really found gender restrictions or lack of character creation that constraining at all. I wouldn't mind playing a pre-made female character in Aliens RPG, as long as I can sympathize with her (shouldn't be hard if I even could play Ripley), but on the other hand I wouldn't mind having a fully customizable character creation process a'la BG as well. It's all about the implementation, and how the presentation is handled. But for the sake of having full control over the functuality of a character, I surely prefer to have the ability to choose my own class and skills. But in terms of Roleplaying, I also can stomach a predefined role, as long as I can sympahtize with this role.