There are differences in geometry but those differences may or may not be suitable to your body type. One of the major differences is that women are assumed to have longer legs and shorter torsos than men of the same height, so women-specific frames generally have shorter top tubes. However, there are men's models that have shorter top tubes as well. Don't limit yourself to women's models. Have a good bike shop fit you and go with the size/geometry that works best for you.