Hi Earl,
It is indeed very subjective. The only reason to use picture styles is to "pregrade" the image.
Since the picture style is being applied before the image is recorded (converted to 8 bit, 4:2:0, H.264)
you are pregrading the raw-data (with your picture style). If you got a very contrasty image (take picture,
check histogramm), you could use a flat picture style to compress as much as possible into the 8 bit image,
if you want to film a subject which is very low in contrast, you should use a picture style like standard or
even contrastier to expand the values in the histogramm to the max (if you do that later in 8bit, you will eventually
get some banding).
