I was lucky enough to go on it -but only once. And it wasn't across the Atlantic, but from London to Paris. It took 3 hours, as we went the long way round. We went from London over Ireland, out over the Atlantic and then turned round and approached Paris from the Bay of Biscay as you can't fly supersonic over land. A few nights in Paris and then back on the Paris - London Eurostar high speed train. I (quietly) proposed to Mrs Zapnsnaps on the flight. She always wanted to go on Concorde and used to love to fly, holding both a PPL and gliding licence. Because the flight was a jolly, rather than scheduled, it was affordable and very memorable. And as you say, sadly, never to be repeated.