I say 240V only solely because it has so little heating power at 120V. It will take a long time to heat up, and the iron won’t be able to maintain a stable temperature in use. The temptation will be to run it hot (or at least as hot as it gets) and rely on thermal mass, rather than feedback temperature regulation.
Even at 240V the iron has a pretty slow regulation loop. It was frustrating trying to calibrate the dial which is *way* off on the slope — setting the position so that 150C is correct results in a setting of 200C being around 185-190C.