generally speaking -- an experienced 4.0 female dubs player can often be more effective than an inexperienced 3.5 male dubs player.
actually let me amend that. an experienced player can often be more effective than an inexperienced player.
since we are on the topic of mixed dubs. the biggest single difference between the sexes is spin. the amount of spin - topspin and slice and kick - is the difference. given a few shots - women get used to faster pace than they normally see. but it takes a very very long time for them to get used to the additional spin.