Thanks to everyone for the great advice.

We have now booked LHR to JFK in First on 2nd May on BA175 and back in CW on 8th May on BA178. Day flights in both directions so we will be able to make a really good comparison of the First and CW cabins.

Have selected 2A and 2K for the outward journey. Any thoughts as to whether this can be bettered (e.g. both sitting on the same side of the aircraft). I know 1A and 1K are reserved from Prems until T-24.

Really looking forward to the trip and thanks again for the advice.