As I understand it, Concorde was closer to coach in terms of seats and leg room than modern business (though with service that matched the price tag) so I can't

As I understand it, Concorde was closer to coach in terms of seats and leg room than modern business (though with service that matched the price tag) so I can't imagine any issues here. If you could fly New York to London in less time than it takes to go from New York to California, while being served well, I can't see that being too much of an issue.