I always had my GSD's done whether or not they were going to be bred from, to monitor my breeding to make sure there were no problems. It is no guarantee, but if you x ray at least you have the knowledge of whether or not the lines are throwing good hips. It can be done at the same time as spaying, provided the dog is over one year old, let your vet know and make sure you take the papers with you.
I also did agility and wanted to know they were ok before jumping them.
In all breeds the more dogs that are scored a better picture of the status of the breed's hips can be obtained.