I have tried reasonably sane & purebred animals Kate- Rottweilers, Shepherds, Mals and multiple terrier types. I've tried the first three in sport and in service. I've also witnessed working herding animals and retrievers/pointers at work. The ones bred for work from workers were better by FAR- hands down, no contest. I've rarely seen a great animal come from nondescript show breeding (although I have) while I've seen it too many times to count the other way. I guess it depends on each persons standard of work though. For my safety and time digging, I'll stick with working lines.