We've had two American showlines, two German showlines (still have one), and a West German working line GSD. Halo is definitely more serious and intense than our previous dogs, and she's also fearless and extremely confident. But I would never expect any dog to actually protect me without specific training. As a deterrent, however, she functions quite nicely.
Keefer 8/25/05-4/24/19 ~ The sweetest boy
Halo 11/9/08-6/17/18 ~ You left pawprints on our hearts
Dena 9/12/04-10/4/08 ~ Forever would have been too short
Are working-line German Shepherds naturally protective ? As in they do not need any special training. Are working-line German shepherds more protective than show-line ?
Working lines tend to have stronger drives than the show lines. This can be a blessing or curse depending on you the owner. To me a clear headed driven working line dog is just wonderful. You have so much to work with and if you put in the time and effort you can produce a solid trustworthy companion. With the drives it is certainly more work and you must be prepared for that.
In addition to drive I prefer the build of the working dogs to the over-angulated show dog rear-ends. Its a shame what the AKC GSD show dog has become in this respect.