Yes, the hybrid vigor is much touted by hatcheries, but I really believe its more for cost saving. Because hatcheries charge more for an order of say 25 all female chicks, than they can for a straight run which is just the first 25 chicks they can pick up and put into a packing box, the sex link chicks can be easily sorted. It takes a lot of experience and a sharp eye to decide which little fuzzy yellow chick is male and which is female at that age...
With the sex-linked chicks, the males are yellow, and the females are clearly more reddish at one day old for example with Red Stars or Golden Comets. This is a great cost savings, but its really causing a loss of the old time breeds IMO which is why I try to keep some real breeds around. I have some Golden Comets, (8 that I got from a friend) I like them, but they wont breed true, their chicks will turn out to be who knows what.
pbjmaker's method at home is at least using closely related breeds, and she can choose to seperate and breed some true chicks if she wants, something the big hatcheries are doing less and less of.
I'm a little biased against how extensively this is being done as if you couldn't tell, I really like the heritage breeds and wish more could be done to save them, though I understand why hatcheries need to make money.