The Koru lounge is superior in the international terminal but its so incredibly busy and the Strata lounge is quiet that if I had access to either I would choose the Strata lounge any day. The Koru lounge in Auckland at night is insane. One of the most insane lounges I ever visit (one of the others being the Auckland domestic lounge - seeing a pattern here).
Pretty much all I want out of a lounge is a nice quiet atmosphere, some healthy vegetable snacks, coffee and alcohol. Unfortunately for Koru, the atmosphere is by far the most important on that list. So if they bumped me I would be plenty happy.