These hybrids are bred primarily for the commercial brown egg market. Yes, they are friendly and lay like machines, at least most strains.
I'm wondering how old they are?
As for breeding, they aren't a breed, but a mutt, so breeding them produces an inconsistent coloration, ie not "true". When these first generation RSLs were hatched, the hatchery could sex them easily because the white chicks were roos and the reddish chicks were pullets. This will not hold "true" next time, if there is a next time.