I think it's ok, but there seem to be a lot of generalized comments, and I'd like to know where they got their information from. "Police lines" might not make good pets for the average family, but they don't even mention that. They say that the dogs themselves are unbalanced, lack control, and are violent. Any dog can be a "bad" dog. I think stress should be more on choosing a dog that fits your lifestyle, and then raising it properly.
One thing I was curious about, the description said to avoid breeders who supply Schutzhund clubs. Don't people bring their own dogs to a club? How does a breeder supply a club? Maybe I missed something.