120 volt ballast versus 240

Was wondering if anybody knows if there is a difference in power consumption with 120 volt ballast versus a 240 volt one. My electronic ballast are both 120 and 240v. Research that I have done says that 1000 watt light draws about 10 amps but the same ballast plugged into 240 only draws 5. Are there any other advantages of using 240 such as longer life span for the ballast and bulb, does it run cooler etc?

wattage = amp x volts If you double volts and half your amps you get the same wattage consumption. lower amps is safer