I thought I replied here, but I guess not.
Just to add my two cents to the conversation:
When I started keeping chickens two years ago, I bought the last eleven chicks that
TSC had; they happened to be five Golden Comets and five White Leghorns (and a Bantam Cochin Frizzle).
The Comets produced 4-5 eggs per week per hen in the winter, and 6-7 eggs per week per hen in the summer.
The White Leghorns produced 4-5 eggs per week per hen in the winter and 6-7 eggs per week per hen in the summer too.
The main difference between the WL and the GC was that the WLs seemed to be more ready effected by changes in daylight (quicker to stop laying, but quicker to recover once the light picked back up again; even cloudy days effected them. The GCs, on the other hand, not as readily effected by changes in daylight; there was more of a delay in their laying slowing down.
For instance, if there was one cloudy day, the WLs wouldn't lay the next day, but the Comets wouldn't miss a beat; however, if there was a cloudy week, the Comets would lay a day or two into the cloudy week, but it would take an additional day or two beyond the WLs picking back up.
If I had it to do again, I would do the same thing. If I wanted just hens for eggs, I would buy half a dozen each of WL and Red Sex-Link pullets every year and cull hens when they stop laying. I free range, so I would kind of have to buy more than someone who kept their hens in a run to replace losses due to predation. (I do put my chickens in a secure coop at night; I let them free range and forage during the day.)
I hope that helps you some. =)