
It depends what you want from the dog in the way of traits. Size wise you are likely to get a biggish dog.
A GSD has a strong protective drive, and a Setter doesn't so you might have either a dog that guards or thinks everyone is their freind. The setters I have met are very lively, so you might end uyp with a very hyper guardy dog. Now if there is nervousness in the mix then that would not be good with the guarding instinct.
You would be better able to judge if you can meet both parents, and assess their temperament. Try and imagine a pup with the worst traits of both it's parents, and if you can live with those then if the pup is better than this then even better. :D