I cant's see why one system is more useful than another.
what matters is the numbers mean something to you.
I also can't see using both.
I use F. I report in F. If my friends N.of the Border use C , I don't mind. if its really important for me to have a feel for their work in C Ill look it up and change it
to F.
having a personal feel for both would use up valuable energy I try to save for finding my car keys.
but to each their own. Tastes the same Out of the Bag Id guess.