DB 757
Remember that the BA product is a 32 seat business class service, those clients who are high spending, if they wish to fly from JFK to Europe, why would they transit through LCY, they would simply fly with another carrier to their European destination, or transit through LHR T5 which is a very pleasant experience. I hope the LCY JFK route succeeds, but I am not convinced it will, after all the very market they are trying to atrract, most have gone bust or about to be locked up for a long time in the slammer.
FF