I was thinking this morning of the Greek "unity of virtues." Virtually all of the early texts which discuss church order emphasize the importance of virtue, the all presbyters, including the presiding-presbyter (this is Afanasiev's term for the person who eventually became what we now call 'bishop') are models of virtue. The comparison between 1st Timothy and the Onosander's list of virtues appropriate to a general reveals striking similarities. Additionally, Onosander and Timothy's lists are typical of similar lists found throughout the Greek world. The significance of these lists is that there are no particular virtues which are essential to church leadership, but all are necessary. This is part and parcel of how Greeks think about virtue: it is essentially unified, you cannot practice one virtue without another.
If we assume that males are better able to practice some virtues and females another (which is another assumption of Greek thought), then the unity of virtue is broken. When Paul says that in Christ there is no Jew or Greek, slave or free, male and female, he is rejecting a Greek ontology that says that we have essential natures which are only capable of certain kinds or levels of virtue. Chrysostom berates men for allowing women to surpass them in virtue (the word comes from "vir" - male), but also acknowledges that women are no less able to embody the virtues of Christ than men. He is a classic example of a Christian caught between the assumptions of his culture, that men are best equipped to exemplify virtue, and the Christian experience that all transformed by life in Christ to become people of faith, hope and love.
Underlying a male priesthood is this ancient assumption of an ontological difference between male and female, and a consequent inability for women to engage in presumably "male" virtue. Putting aside the question of whether the priestly office is actually male (the quick answer: not a single early church theologian thinks this - but that is a different discussion). The damage is not only to women, though I think it is certainly more obvious how restrictive these definitions are on females. The idea of virtue as 'male' says to men that it should be easier for them to be virtuous. I know of no healthy male that believes this to be true. Strangely enough, this is precisely what underlies the theology of Paul Evdokimov. In his valiant attempt to take feminism seriously, he turns all of this on its head, portraying women as more easily virtuous, and the saviors of men who without their intercession would be imprisoned in a hostile and inhuman 'male' world. In the end, his theology is no less restrictive for women, and it is also quite insulting to men.
Any division of male and female into "modes" challenges the essential unity of the virtues in love (the highest of unified Christian virtues), and undermines the ability of women and men to become fully and lovingly human.