Jim,
there is no advantage to not owning a breedable girl. We really wanted to keep one. However, with only two girls available to sell and 5 homes that wanted girls, it only made sense to sell the two girls into homes where they will be either the only dog or one of two.
That leaves us -- as breeders -- with no dogs to breed. Which makes it hard to continue our line! However, we do co-own girls that live with their primary owners and one of the stipulations in our co-own contract is that we get to keep a puppy out of their breedings -- either to sell ourselves or to keep ourselves. In the case of Sundance's sister, Juneau, her owners would actually like us to manage the breeding and whelp the litter. It's something we do pretty well.
So, that's the next best thing to having another girl in our home right now. The main advantage to co-owning is that we don't have to take the risk that the puppy we keep doesn't turn out either as a show dog or in terms of health clearances. We don't breed unless our dogs have proven themselves in the ring and have gotten their clearances. With a co-own, we have options of several of the girls which gives us the chance to match the right one to the right male.
I hope that answers your question. We constantly struggle with the fact that we're exhibitors and breeders but we're also not interested in breeding a lot and we try only to breed for ourselves and to improve our line. Plus, we're getting to an age where breeding, whelping and letting them go is really hard!
Something not everyone is aware of is that the owner of the bitch actually picks the stud dog for breeding and pays a stud service for his use in breeding. The owner of a stud dog has to have breeders who want to use his dog. Even if we were to want to breed Sundance, we would have to find a bitch whose owner wanted to breed to him.
Anyway, the pups are 6 weeks old today and it just hit us that they'll be leaving in 2 weeks. Gasp! It's too soon!
Jim