Some addition from Austria: What I see as the main problems of 120V is: Higher loss due to the lower voltage and the higher currents, hence lower maximum wattages per circuit. It's really hard to get a 230V/16A circuit with a maximum load of 3680W to overload, but quite easy to do the same with a 120V/15A circuit which uses the same wiring.
Would rather fit the violations section, but I once saw an American making 12 receptacles out of a standard duplex recptacle, using various extension cords, power strips and taps, most of that stuff ungrounded, only the last extension strip in his chain grounded. No idea where the ground prong had gone...
i had to live in that room so my first thing was to look for the breaker panel. Just in case...
It was really scary.
In facz you could really add that statement to the "famous last words"-collection. There should really be surveys about how many people die stating "But it's only 120 Volts..."
Especially when they hold a black and a red wire in their hand...
*sarcasm*
