I have worked on both 480V and 600V in industry in Canada.
600V is lower cost in the long run, but it scares the heck out of me. Just kidding.
480V is 277V to ground, 600V is 347V to ground. We electricians get most of our shocks to ground.
347 is the most dangerous voltage to work with. Anything higher, and it 'throws' you out of the circuit, anything lower you still have muscle control to 'pull' away.
I am told 347 just keeps you in the circuit until either you or the grid say 'uncle'. Guess who usually wins.
