Anecdotal rther than aerodynamic evidence here - but there was a noticable buffet as one decelerated, accompanied by a significant step in thrust requirement. That point was where we (flight crew) decided we were in vortex lift.
Typical speeds would be 270-280 kts at TO mass and about 230-250kts at landing mass.
I'm not naive enough to believe that it was a 'switch' in aerodynamic modes, but the outcome felt like one.
I'd be slightly surprised if there was much of a vortex at M0.95 since the alpha was fairly low here and I would expect there to be plenty of shockwave activity on the upper surfaces which would suggest that a standing vortex would be likely to be badly disrupted.
Anyone know some definite answers?