I still prefer miles and gallons to km and liters but if I am doing a precise measurement I will use mm. In electronics everything is metric so that is what I use.
Conversion errors kill spacecraft...right?
Wonder if this would ever drive a similar change in the States.
I still can't think of fuel economy in anything other than mpg despite not knowing how many gallons are even in my tank.
It's just so much easier to do math and not nearly as confusing when you're trying to communicate with someone. Pound? Wait Pound Force or Pound Mass, wait maybe I meant a Slug. Horsepower, wait what. It's like someone randomly pulled names out of a hat and assigned them random numbers.
I've never needed to know the amount!
But then again - who's used the pythagorus theory since leaving school? :-)