I agree that it's very dependent on the rider. I generally get up to (my slow) speed quickly on new tracks, whereas one of my friends need a lot of time to get used to a new track (or a good tow around). Figuring out the hooking sweeper (Turn 9) on Big Willow did require some personal tuition from Cobie though.
DL: It's pretty much down to yourself. I've never taken a CSS course on a track I knew ahead of time, so I might not be the best person to answer. You could actually argue that having a new track to learn is beneficial, because you don't have old & bad habits from riding there previously