The engineering timeline of the Radeon R9 and R7 Series, which feature Project FreeSync-compatible display controllers, establishes that FreeSync predates G-Sync by a healthy margin.
Now where have I heard that before...
...which means frame presentation to the user will never be delayed or impaired by time-consuming two-way handshakes.
Admittedly, that comes from the response to "does FreeSync use triple-buffering", but I don't recall G-Sync needing a two-way handshake. IIRC, the GPU pushed the new frame out to the display, at which point the monitor displayed it.
Now don't get me wrong, I'm excited about G-Sync, and probably would have bought a unit when they became available, but I recognize that G-Sync is an inelegant hardware solution to a complicated problem. The whole point behind the custom scaler chip was due to how current monitors behave: there is
no allowance for variable refresh rates in the hardware. FreeSync-on-that-demo-laptop worked due to how the GPU was (basically) directly connected to / driving the display (eDP?), and could
alter its refresh rate accordingly.
Either way, this is a great technological development. As opposed to 3D HDTVs, I think variable refresh rate televisions will
be a big deal. Watch "The Hobbit" in your home at 48fps? Awesome!
I too eagerly await the updated monitors