Trust me, as a Canadian I sure didn't forget about Robertson. It's the screw of choice up this way by a long shot other than for drywall work where the screw guns are set to let the screw advance itself off the tip. For every other application Robertson is head and heels over all the rest. The screwdriver's square end is slightly tapered so you can press the screw onto the driver and it'll stay in place even when holding the driver screw or driver drill down for true one handed starting while your other hand does something useful like hold the parts together.

Is Robertson starting to make inroads in the US other than as "security screws"? I had to laugh a little when I saw that a few years back.