Coming from a long automotive background, I use both imperial and metric measurements for sizes. I do some design work in CAD, and prefer metric there, because it's much easier to work with.
I still prefer imperial for temperature, speed and distance. I also prefer in/lbs and ft/lbs over Nm for torque, mostly due to the calibration markings on most US made torque wrenches, although I have a set of Park Tools torque wrenches in Nm just for use on the bike.