Usually if I'm going to cap the sexes, I tend to cap it for current in game players rather than for any new people. And I've actually found that its worked pretty well. It encourages my current players to either try a character they might not normally, keep things from getting too unbalanced in game gender wise, and if they are determined to pick up another of that sex they're forced to wait a bit and usually their app ends up being better because they've had the time to look it over a few times before turning it in. Not to mention that it doesn't push any new players into playing one specific sex. There are a few flaws with this, I'll admit it, but for the most part, it's not a terrible option.