As a human, the first thing that I hate about this interpretation of "human readable" format is inconsistency in the number of significant digits. One digit after decimal separator is simply wrong, as when you jump from 999.9 MB to 1.0 GB you go from 4 significant digits to 2, instead it should be 1.000 GB, 10.00 GB and so on. This annoys me enormously when I upload things to Google Drive from Android phone and look at the number of data transferred as as soon it becomes bigger than 1 GB digits stop changing and I become anxious that it stopped the transfer and my Windows Phone nostalgia jumps over the roof (as WP was never infected with this problem by virtue of not using Java, and OneDrive on WP explicitly showed current connection speed, and frozen connection never caused any strange problems with uploaded files like it does on Google Drive on Android).
As a human not from US, the second thing I hate here is lack of locale parameter to pass to formatter as decimal separator is different in different cultures, and in the world of cloud computing the locale of the machine where the code is run is often different from the one where the message is displayed.
As a human from a culture using non latin alphabet, the third thing I hate here should be obvious for a reader.
I don't think it makes sense to talk about significant digits here. And while you are correct that you should not go from 999.9MB to 1.0 GB you are incorrect about your reasoning and your correction is also incorrect. Significant digits signify reliability of the numbers. So if your measurement is accurate to the +/- 50kB as indicated by 999.9MB you should then move to 1.0000 GB (5 significant digits). So it should be 10.00GB and 1.00GB not 1.000GB, because the reliability should not change between your measurements.
As a human, the first thing that I hate about this interpretation of "human readable" format is inconsistency in the number of significant digits. One digit after decimal separator is simply wrong, as when you jump from 999.9 MB to 1.0 GB you go from 4 significant digits to 2, instead it should be 1.000 GB, 10.00 GB and so on. This annoys me enormously when I upload things to Google Drive from Android phone and look at the number of data transferred as as soon it becomes bigger than 1 GB digits stop changing and I become anxious that it stopped the transfer and my Windows Phone nostalgia jumps over the roof (as WP was never infected with this problem by virtue of not using Java, and OneDrive on WP explicitly showed current connection speed, and frozen connection never caused any strange problems with uploaded files like it does on Google Drive on Android).
As a human not from US, the second thing I hate here is lack of locale parameter to pass to formatter as decimal separator is different in different cultures, and in the world of cloud computing the locale of the machine where the code is run is often different from the one where the message is displayed.
As a human from a culture using non latin alphabet, the third thing I hate here should be obvious for a reader.