I'm just offering some starting points for Robi--obviously, conditions, sea state, mast wing section, trap/non-trap, wild/non-wild, spinnaker cut, spin sheeting point, etc, etc all play in. I find I that I really benefit from loosening the outhaul, not taking it all the way off, just to get the main a bit fuller. This is essential because in any wind over 10 knots I'm sailing upwind with my main set up very flat and streamline.

Bottom line is that every rig is a bit different, and different condition and boat speed can put the apparent wind further forward. Tell tails tell the tale of truth.