according to ted talbot's book the B1 bomber couldn't hit the speeds that the concorde regularly cruised at. much to the eternal frustration of the americans.
Not only that, but when Talbot first saw it he said "how do you get that beyond M1.6?". "With difficulty", came the reply. "I'm not surprised" replied Ted. "Your boundary layer diverters are worse by far than the ones we started out with on Concorde, and
they were bad! Also, with the intakes effectively on their sides your intake shocks will greatly deepen the boundary layer".