Dave, given your requirements, and the changes to the QF points earning on BA and AA after 1 Jan, I would seriously consider AY via HEL.

The downside, for a QP regular, is that the AY flight LHR-HEL departs from T1, so no F lounge. But as a SG you will have access to the BA Exec Lounge even when flying AY and the bar is open! Nice little AY lounge in HEL.

AY were very good to me and the family in Y. Food and service were quite acceptible.

Oh yes, the A319/320 LHR-HEL will likely show the takeoff and landing on the drop-down screens from a camera in the front undercarriage - great to see if you have seen before. I am not sure if AY do this on the MD11 aircraft they use HEL-JFK. And you get to fly on another aircraft type not common in Australia - the MD11.