Some people say the leghorns are 'flighty' , doesn't bother me not a big deal they're just a little more active and jumpy. Never found them to be aggressive actually very non aggressive compared to some other breeds. I've heard the Mille Fleur leghorns are less flighty, but hard to get.
But if your not into them the Barred Holland also lays white eggs and is a calm dual purpose breed, just doesn't lay as often as leghorns. California Grey's and Whites are another option. Strombergs hatchery has the greys and whites.