Well, I want my chickens mostly for eggs, but I wasn't sure I would like the leghorn temperament, so I got a mix of RCBL, NH and Barred Rocks. Turns out I like all of these breeds, but so far the RCBL are laying at 60% compared to 90% for the brown egg layers - and, of course, the dual-purpose are generally more calm. I am attracted to heritage breeds, as opposed to newer egg-laying crosses for both tangible and intangible reasons. Are the hatchery heritage breeds really more like a production bird - say, a "Production Red" than a true New Hampshire? What I love about the New Hampshires was how fast they feathered out. I really like the Barred Rocks as hens, but they were SO uneven in their maturation.
From what you are saying, Arrielle, I'm wondering if I might not just work with hatchery stock, selecting for things like health and reasonably good egg production, and maybe try to get a true heritage rooster at some point to improve the birds I have. I, too, thought I'd want dual purpose for meat, but I got straight run and found that the 7 roosters were causing problems (biggest chasing the others away - way away) by the time they were 4 months old, and I ended up butchering some pretty scrawny birds. Unless I want the birds for meat, I'm not sure that the cost of true heritage breeds is worth it for me, especially if egg production is lower. Yet, I've heard from several on this and another forum, about how different the true heritage birds are from hatchery. But, it sounds like it might be mostly SOP and size that is superior.