I think the electronic industry went with metric long before I picked up my first circuit board, and this is not an argument with metric, as I think it is the way to go. My beef is using too many units. Pico and micro seems enough. So we have to write one more digit. I don't mind writing that extra digit, but at least I know what I am working with. Everytime I see nano I have to stop and make that mental calculation.
I am lazy and nano just makes me have to work my brain more, and it is just plain tired...