Charge times are improved at deep to moderate discharge states. Little improvement (but not necessary for charge times expressed to be realized) at 80-100% SOC (state of charge).
EDIT: @clouddrover You asked "So is the Model S and Model X charge time improvement across the entire charge curve or just sections of it?" I provided a response to that question. Sorry if you thought I was restating what you already said, that was not my intent. Please excuse my exuberance, this is one of my few passions (rapid electrification of transportation).
EDIT: @clouddrover You asked "So is the Model S and Model X charge time improvement across the entire charge curve or just sections of it?" I provided a response to that question. Sorry if you thought I was restating what you already said, that was not my intent. Please excuse my exuberance, this is one of my few passions (rapid electrification of transportation).