The Return of Supersonic Travel
thedetechtor.com
thedetechtor.com
Add the time at the departure airport, 3 hours for international travel, and the time at the arrival airport for customs and collecting luggage, lets say another 2 hours, the difference in total journey time is 8:30 versus 11:30. This is definitely not a 50% reduction.
The fastest way of course is to use a private jet.