I accept that STN can offer different customers to LGW, but there is a danger that they could just dilute yield. Why not consolidate at LGW, compete on underserved routes from Europe like Austin, Las Vegas and Seattle, using the short-haul network you already have and shuttling holidaymakers to Florida? Why launch a new base to slug it out on LON-NYC with BA(et al) and VS(et al). LON-MIA/NYC/BOS, for example, are available throughout 2019 for £279, return including taxes and meals (but not bags). More capacity between London and large US cities doesn't seem like a great way to do anything expect set fire to cash.