Yep I am getting one in the near future (6-8 months from now). I have only a few first hand accounts with them, all of them amazing dogs. I have read that they can be much like the GSD as in some lines are skittish and nervy. I have never seen one that is that way though, I'm sure they are out there. They tend to be stoic dogs, as you have seen, but they bond extremely strongly with their owners. They are listed as being both a herder and an LGD. They make excellent watch dogs and can be very intimidating. Their size alone is enough to deter most people. Their training needs, from what I have read and had people tell me is a bit like a GSD but more independant thinking, so good leadership and making training interesting is how to get training done with them. But really, who knows? I've never owned one and every dog is an individual. We'll see how it goes.
I have researched breeders in the US and Canada. I am looking for a dog that I can do a sport with so there's only one breeder that I settled on. Ruling out the other breeders was pretty easy, except to say one kennel listed in Canada seems to have good drivey working dogs. I have seen one specimine from my choosen breeder -- that dog is amazing, in both his choosen sport as well as being a very active Therapy dog. Very dual purpose with very good temperament.
I have to talk with the breeder a bit more, and find out more about her lines. I have had several people tell me that for my needs, there's only this one breeder. I will be driving to pick up my puppy so a road trip is in my future. I am so excited.
I won't openly discuss breeders here, as I may change my mind later. So if you want more information on specific kennels you can PM me. I will be more open about my puppy when I get closer to getting one.