What do you want the dog to do? Protect your livestock from predators or herd or be a watchdog? The answer depends on what you want. I have a Berner ( Bernese Mountain Dog) mixed with boxer and he is a gem of a dog. I could leave all the doors wide open and nobody would dare come in the house.

They are pretty expensive and you may not find a purebred at a rescue.

My friends have had several Berners. One caveat, which you are probably already aware of, is that they don't have very long lives. They can be couch potatoes and I adore them, but they are large laying around the house.

I can't speak for Berners but can warn about the Aussies or herding dogs in general. They are fantastic dogs and so so smart, but will instictively herd anything and everything that moves including YOU! You need to know how to handle them and be consistent as they can be a bit persistent.

Huge difference between Berners and Corgis!

We are on our second Cardigan Welsh Corgi, and we are completely hooked on the breed. Ours are strictly house pets, but certainly have the skills to herd - we used to board our first one with a woman who raised golden retrievers, and our Corgi herded four Goldens all over the yard!

Don't own one personally (a bit large for my accommodations :-)) but know two Bernies quite well :-) They are big, sweet, good temperated, lovable and immensely trainable dogs. Great around kids. Depending on temperament and breeding, they can be much more of a lap dog than a working dog and that herding instinct is sometimes almost nonexistent. But they do need some room and routine daily exercise.