Hi MB2002,
This article
http://www.davi.ws/avionics/TheAvion...ook_Cap_11.pdf para 11.8.1. has a description.
It sounds beautifully instinctive.
"The unique 777 implementation of maneuver demand and speed stability in the pitch control laws means that:
• An established flight path remains unchanged unless the pilot changes it through a control column input, or if the airspeed changes and the speed stability function takes effect.
• Trimming is required only for airspeed changes and not for airplane configuration changes."
When stick free, it sounds like the aircraft will return to the last trimmed speed.