"Should men, or should women, dominate the church?" is the properly-formed question on this topic - the question which sets into proper perspective the mass of comments and reflections and policies which have clustered around the topic of sex roles in churches.
(Note that for Christians this is essentially a question of the church as an organization, and not the religion itself - it is a mostly question of good order in the institution. At a spiritual level this discussion melts away; or, at least, transforms qualitatively.)
This is only an active question in some religions, of which Christianity is one - because there have been a wide range of balances between men and women in domination of the Christian church, and in different areas of church activity.
I had been reading a Mormon blog in which a woman complained that - in terms of the LDS church - she, and her daughter - felt (ahem) hurt by the maleness of the priesthood; given that the priesthood was of such vital importance: for her nothing could make-up for this fact of inequality, of non-sameness.
Musing on this, I realized that the premise of this debate was mistaken and dangerous; because when the question is properly framed there are only two valid perspectives.
Either 1. the Mormon church should remain dominated by men, or 2. it should instead become dominated by women.
And this is a question to which empirical evidence can be brought - because there are examples on both sides. There are Christian denominations and specific churches that are dominated by men; and there are those which are dominated by women.
In between there are many Christian churches in which the balance is towards either men or women and where the situation is clearly moving in one direction or the other.
So there are men-dominated churches in Mormonism, as mentioned, and Eastern Orthodoxy, and some Conservative evangelicals.
And there are women-dominated churches in all liberal Protestant denominations. (Woman dominated means not that there are no men, but that male leader must primarily be compliant to the agenda of being ever-more women-dominated.)
I see the Roman Catholic church as being a mixed state and moving towards woman-domination since Vatican II. Despite counter-currents I do not believe that this this movement has stopped. So, the male priesthood has become increasingly feminized and compliant (conducted according to principles derived from women) for several decades; a situation which happened earlier and more completely in the Romanized Anglo-Catholic wing of Anglicanism
From the above, I think there are sufficient example to infer the necessary medium- to long-term consequences of men versus women domination of churches in terms of the size, vitality and growth of the institutions
So, the discussions on sex roles in denominations should not occur in a vacuum of abstraction and at a theoretical level. The consequences of changing a church from male to female domination are indeed known hence predictable.
For instance, we know that the nature of an institution is fundamentally shaped and changed by a shift from male to female domination.
And we know that there are no long-term-viable examples of mixed male/ female domination - there are only transitional states as a church moves in one direction or the other.
The long-term-viable examples (I mean church institutions which survive and are strong for several generations) seem to be either male-dominated or female-dominated institutions, tending very much towards single sex institutions, or rather sub-institutions within churches (like church schools, nunneries, nursing sisters, the Mormon Relief Society).
Things are actually very simple - once transitional situations are understood! Either an church is organized around the principle of domination by men or by women.
In practice this domination will always allow for exceptions, to varying degrees; but since equality and impartiality are impossible - we have here an apparently immovable principle in human affairs: either/or.