They sure are nice looking butterflies! I have only seen one, last year in the southern/downhill part of Aranda Bushland Reserve (south of the Snowgums) but camera battery had just gone flat! For some reason, find them quite mesmerising...
They are quite stunning, generally much more abundant in the Canberra region, but the high rainfall probably contributed to low numbers of flying adults in the second half of last year. If rainfall returns to average or below, then expect to see a lot of them. You can see them flying in all months of the year in Canberra, one of the few butterflies that do so.