Sonic cruiser would make transcon TURNS possible. That would immediately double the productivity of crews AND remove hotel expenses completely. It would be huge. 1 plane could do 2 round trips in a day and then some...
Right now transcon lines from NY involve a leg to the west coast, sit 30 hours come back... Not very efficient use of resources.
I know my airline would burn tankers full of fuel to get that kind of productivity out of its crews and aircraft.
Cheers. .Wino