What is the benefit of flying a set ground speed?
GS mini doesn't fly a set groundspeed, the function ensures that the total energy of the aircraft is maintained throughout the approach.
In plain english the actual GS won't ever decrease below the planned landing GS (VAPP-wind) so that if there was a sudden decrease in wind you wouldn't find yourself falling out of the sky.
The disadvantage is that the actual VAPP can be very high initially, and it can jump around if the wind is gusting.
S.