Actually MachineClaw, on mine, I could see only one more box than on yours (clipping at 16% vs. 19%).

Id asked the question because I suspect (hereby screwing up the survey by predicting an expected conclusion) that most folks DO tend to normally run with their black levels slightly crushed. Meaning that if you rendered based on a correct monitor, your work would indeed appear too dark on the screens of most viewers.

Since posting this, Ive tweaked the brightness & contrast on mine to see all but the last two black boxes but not sure I like it this high (everything now looks just too damn bright & cheerful).

elizabyte mentioned gamma, but that's really not addressed here and would be a whole 'nother bucket of worms (hence the joke in the topic line in #5). So far weve only been concerned with the correct values for the end points of the grayscale. Gamma curves would refer to the nonlinear factor in the transition from black to white.

In other words, when Zero Black and 100% White look correct on your monitor, is 50% White still displayed at middle gray?
(see the pic above)

AFAIK, only fancy-schmancy monitors have user accessible Gamma Correction adjustments, (not the cheapies I use) but this only further points out the great unlikelihood of anyone ever actually seeing your work in the precise manner in which you intended it to appear.