Vortex Lift
There have been a couple of references in this fascinating thread to vortex lift.
I'm sure we've all seen videos of Concorde arrivals and departures where you can see those huge 'wing tip' vortices. It's pretty obvious that at supersonic speeds the airflow must be very different.
Was there some particular airspeed where the airflow pattern changed markedly?
If you decelerated through that speed in level flight did you get a sensation of a sudden increase in drag or need to increase attitude significantly?