I use both (or either), depending on what I am doing.

In Canada, we say that we "went metric" many years ago, but in reality, we just added metric to our long in use imperial system. We by 2 x 4 lumber and space them on 16" centers. We buy 4 x 8 sheets of plywood. But, we buy gas in litres and cold meat in grams. We measure temperature in Celsius, but we don't measure pressure in millibars. We use kilopascals, which are neither metric nor imperial. When asked our height and weight, most of us still say 6' and 175lbs. Ask any woman how much weight she wants to lose and it will always be 5 lbs, not 2.5 kilos.

In short, I don't believe we really converted at all. Maybe in another generation, it will happen, but it won't be in my life time.