Connections vary, but its not unusual to have 20-30 pax for LPA from LGW who travelled in the night before from across the next work, NAS see little risk in this due to their exceptional on time performance, this confidence regularly allows them to position crews from one base to another to operate a flight within 90 minutes of STA and this planned not reactionary.
NAS accept that from time to time it will go wrong and if it does no if's or but's they put them up in a hotel.
With regards to JFK well lets see, but the growth on inter Scandinavian into LGW has taken business from SAS & BA at LHR and a lot of these are suits.
People only a few months were ready to paint this (NAS) as Aer Lingus V2 but if the numbers are anything to go i think they are very much here for the long haul in every sense of the word.