Was lucky enough to fly BA First Class from LHR to JFK back in 1986, as a 16 year old; needless to say it was great.
Flown lots of BA Club and other carriers business class longhaul, since then and whilst things have moved on in the round, I am not sure the overall experience is special anymore. But it is very familiar.....
That said I used the BA LCY-JFK service a couple of years back and that did have a bit of magic about it and felt genuinely special.