Aside from it being more humane to raise birds that don't suffer health issues from rapid growth, slower-growing meat birds like these provide more nutrient-dense meat (vitamins D and E, plus a better omega 6:3 ratio).
Although they take 15-18 weeks to finish out they eat close to the same amount of feed that a faster growing meat bird such as a cornish cross does, simply slower, over a longer period of time.
I monitored how much my last batch ate and calculated that it came out to about 5$ in feed per bird at a rate of $20/50lbs. (They were free range/pasture raised so they foraged a portion of their diet) I've heard of feed mills selling chick feed for 13$/50lbs so the feed cost per bird could easily be dropped to 4$/bird at that rate. 4$ isn't a bad deal for a 5lb "ready to cook" weight!
These birds are also more hardy, being able to withstand disease and temperature extremes better than a cornish meat bird. Guaranteed little to no loss of life/profits/food.
I recommend feeding starter grower until 10-13 weeks of age before switching to an "all flock" or "meat maker" feed.
Finish weight: 7-9 lbs
Coming from a tested clean flock not treated with antibiotics, vaccines, or medication of any kind.
Let me know if you want to fill your freezer with humanely raised nutrient-dense high quality meat!