According to metrics; the English units of measurement have a major
drawback; in the complexity of converting from one unit to another:
Now of course that is true for converting units of Length into units
of Force, and/ or units of Time, and would indeed require some kind of
magic; but converting units of length into longer or shorter English
units of length is easy; just by moving the decimal point; one or more
places to the left or right.
Whereas the metric system has a different name for every single
decimal point, the English system reserves different names like
inches; feet, yards, and rods for special purposes, and generally uses
the foot as the standard; a standard that has wide application.
Because of this "disadvantage" the rest of the world is gradually
switching to the "much simpler" metric system. There are outstanding
proposals to do away with the U.S. Customary System and replace it
with the metric system. The majority of countries are in the process
of this expensive replacement even as I write:
All that's missing is the cooperation of U.S. citizenry: We all know
how we hate and suspect changes. "If it ain't broke, don't fix it",
and the foot-pound system certainly isn't broken: Its able to give
decimal accuracy equal to any system that ever was, or ever will be.
Let's keep it
The metric SI system definitions, standards and specifications require
constant tinkering, and they never _will_ get them right: Even if they
resolve the contradiction between force and mass, the newton is too
small, and the meter stick is too long!