Frank & Brian+,

I agree that within the Anglo-Saxon Church, abbesses seem to have had a prominant role (though, the Frankish Church had their own abbesses, normally from aristocratic backgrounds).  I don't know about the occurrance of abbesses within the Irish Church.  Hilda's role in the Synod of Whitby is, of course, famous, but I don't think we should allow it to exaggerate what was going on.  Until the 7th-century, convents were exceptionally rare things.  Even during the height of founding female monastic communities (the 7th century), they remained a rarity (located also more often in the thoroughly Roman South of England than in the North), almost completely vanishing with the arrival of the Vikings.  It's a shame that we don't know more about Hilda, she must have been a remarkable woman.  The inclusion of abbesses at synods is probably a remarkable thing.

I think Mike+ put his finger on the most remarkable thing about early Irish Christianity: its extreme penitential nature.  I'm not sure any other church produced anything like the Culdees, though perhaps the Desert Fathers come closest.  

Again, let me stress how remarkably little we know about Briish Christianity.  If not for Bede, Gildas, and Nennius we'd have very little contemporary to draw upon.  Both Bede and Gildas were trying to make points with their writings that influence the way characters and customs are presented.    I think it noteworthy that when St. Columbanus went to France and founded his monastic communities, his style of Christianity wasn't terribly foreign to the Franks.

Mark+