RiceI would probs go with -2 to -3 from true centre, but really it's Australia so I would probably go -2 as the off piste in Australia isn't 'steep and deep'.
The closer you are to the centre, it is waaaaay easier to ski switch, and I find landings more comfortable closer to the centre.
Unless you bring those skis overseas (deeper snow), having them slightly forward from the recommended marker shouldn't matter as it's only the flotation in deep that is affected (friends that have centre mounted ski/talking to brand reps/shop owners).
I had a friend that skied on a pow day with centre mounted skis, and he said it was fine.
If your really bummed, I would pay the extra $50 for any marker schizo binding.
Where do you ski in Australia? NSW?
I ski at Thredbo..
Thanks for the advice. I'll probably go around -2.5. I ski Thredbo as well but i get there in two weeks.