Flew LHR to JFK on Concorde in 1996...
Albeit on a charter rather than a scheduled flight Back then Goodwood Travel used to charter it and offer weekends in New York - Concorde out on Saturday, two nights at The Plaza then back on a 747.
Cost was c.£2000 THEN but it was worth every penny. Wake up on Saturday and a civilised time, check in for a 12:40 departure. 3 hours 20 to JFK, so arrive 16:00 UK time. UK had gone to BST but US had not yet gone to Daylight Savings Time so six hour time difference so 10:00 in New York. The usual (for then) hour through immigration at JFK then into town, check into the hotel and was wandering down Fifth Avenue at 12:30 New York time having woken up in my own bed in the UK the same morning...
As others have said Concorde did not fly well subsonic and it was noisy in the cabin. No IFE but who wanted films/TV when you were on Concorde? Seat pitch wasn't that great either. I remember them lighting the reheats, two at a time, over the Bristol Channel resulting in two gentle nudges in the back. As the Captain said we were already at 45000 feet which was beyond was most airliners could reach. They then let Concorde 'cruise-climb', rising as it burned off fuel; we got to 58000 feet that day...
REALLY glad I did it...