Freaking Aussies are EVERYWHERE! I don't get it. They get free airfare or something?
If you're going with your GF, you won't be sharing a room in England, but in France and the Netherlands, they're cool with that.
Breakfast varies, from full-spread, impossible-to-stomach food in England to simple pieces of delicious bread in France. Go figure.
I hear the hostels in Scandinavia have co-ed saunas. Be almost worth the trip just to see that.