I have used both the Girls and Boys XLs. I like the Girls better because they have more stuff down lower to absorb than do the boys. The Boys are designed to absorb where a typical pre-teen, undeveloped boy is most likely to squirt. But if you have hit puberty, most likely you will want to point the equipment down. In that case, the Girls have the absorbing zone where you need it.
Besides, the girls prints are fun to wear.
Kenny