I just got 6.xx on Thursday, so I am still figuring it out. But my initial impression after 200 mi is that it seems to initiate more smoothly, but the gauge still shows the same amount of regen. I am not yet seeing a change in my energy usage. That will take some time. When I first drove her after the update I felt as if I were pressing the brakes harder to stop. But by the end of the day I did not find myself doing that and it seemed quite similar to prior to the update. I do have the general impression that the car is easier to modulate on my mountain roads: a bit more predictable, but not much.
TDial, could you check your car manual - accessible from the center display in the car or "My Tesla" page on teslamotors.com - to see if the new brake system still includes hydraulics, or it is purely electromechanical (electromagnetic) brake system.
Based on my review of the manual version associated with my car manufactured last July, the hydraulic brakes are mentioned on the following pages:
p.93 - On the Maintenance page there is recommendation to change brake fluid every 2 years or 24,000 miles, whichever comes first
p.109 - Includes instructions on checking the brake fluid
p.126 - Includes brakes specs
Thanks