Being a UK person of a particular age, none of the set unit definitions are comfortable to use: I use miles and mph for long distances, but metric for everything else (short distances, weight, height, temperature ad nauseam).
So can I choose what unit to use for each function? There should be no technical reason why this can't happen (unless the backend code is really strange, it really ought to use metric measurements and convert when viewed), so it shouldn't even be that difficult and means that I (and a lot of people like me) won't have to spend ages trying to convert to archaic units all the time.
And the UK Statute setting, goes some way, but not far enough: us UK people are contradictory - we usually use miles and metres, but can use either feet and inches or cm for height and stone and lbs or kg for weight, depending on upbringing and age.
