Some unscientific thoughts on 16 bit editing from a professional photographer....
since I started shooting RAW with my mid range canon cameras ( 30D and 40D) - my digital
life has totally changed- I no longer worry about under and overexposures as much- even though I always look at my histogram- but occasionally when an ultra white dress fools the camera and is not registered on the histogram in camera correctly I can now recover a good deal of this highlight value...
Color correcting RAW in LightRoom- Color correcting is easy- but also interpreting the image is also...
if I want a brighter high key image- no problem, or a darker more somber cooler image- same there- and through all of it the
color looks good and natural- as good as film was and many times better... and it is because of RAW and high bit editing. My point - editing RAW images for color in 16BIT gives a more NATURAL FILM LIKE quality to the final product.
Color correcting legacy jpeg files in LightRoom...
Recently I reviewed 250 jpeg images I shot mostly in daylight during hurricanes Rita and Katrina- daylight is really not much
of a challenge for a good camera like a 20D- however when I took the images into LightRoom
(BTW the default color space for any image taken into LR- even 8 bit is a 16BIT pro Photo SRGB workspace)
and started to make
more artistic changes to these images- brightening midtones in some- darkening others or pumping up the color a bit- one thing struck me- I could see the richness of the images and my re-interprets in LR- even from the 8bit originals- looked
NATURAL and FILM LIKE....
On the other hand- if you shoot an 8bit jpeg file- nail the exposure and color balance of a typical daylight scene- and do not plan to or usually re-interpret the image- then you will see little or no benefit of high bit color editing... you only get
benefits if you have to depart from the AS SHOT rendition the camera makes...
also - I have been looking at color for over 25 years and can truly see color- I would not expect a beginner to see what I see- nor to have an appreciation for (tonal color richness )... I read those scientific comments about gaps in the histogram- but what we really need are side by side images to make comparisons...if this were done we would not even need to ask this question.