I use both for measuring, partly depending on the distance... but I guess that's because my feet are 1 foot and my arm span is 2m
I wonder if my cubit is 50cm?
I grew up during the conversion process so I can quite happily switch between the two but kids today seem to find it confusing learning about a system that is not widely in use, pretty much because they don't need to use the old measurements in their day to day life.
We got a speed limit increase along the way (30mph went to 60km/h in local streets) and it's taken years to bring it back to 50km/h after compiling lots of statistics that the additional 10km/h contributed to a lot of serious injuries/deaths of pedestrians.