I realize this is a somewhat individualized choice and that monitors are all different. But does anyone have suggestions for general settings for contrast and brightness?

It seems to me that the jungles of Haven have some pretty dark spots, and I'm wondering whether less brightness and more contrast would help me distinguish some of the subtle differences. Also, the truly black areas seem to do something odd to my screen, where they look less black than the immediately surrounding gloom, which tricks my eyes.

OTOH, I suppose I would then find that bright spots would sort of gray-out, like some of the animal cut scenes already look in comparison to the richly rendered surroundings.

Contrast at its highest level.
Brightness depends on your monitor and your preferences.