Basically if you running 240 then your using half the amps you would be if you were running 120. The only time I would do this is if I was running a large grow or if I had to run a new circuit to my closet because I was popping breakers. At that point you might as well run it if you want, or if your running more than one light. What happens with 240 is you run two 120 to the plug instead of a 120 and a neutral, you get one 120 from each leg on your pannel. People think it saves them money on electricity but I have yet to hear someone explain this in a way I understand. If any thing there is less resistance/heat in the wire. Plus I guess you can save money on wire and breakers since you can run a thinner cauge wire since you using less amps, on long runs this would really save some cash. Hope this helps