Providing fuel consumption is not increased, airlines will probably favor the sonic due to increased utilization and lower direct labor costs. Just finished reading a report put together by a member of an aircraft orders groups and does a side to side comparison of the SC vs. traditional aircraft based on BA's long haul schedule out of LHR. Significant cost savings due to the afore mentioned reduced direct labor cost, and better aircraft useability. (ie: no overnight in JHB required, etc).