arch,

i'll add something new based on a recent experience. There is another difference that has nothing to do with the dog itself, but the U.S. club. Unless you are in with the right people, you will be overlooked. I have heard recently about a member of the executive committee actually insert himself into the registration process of a test to insure that dogs coming from a certain breeder were not registered in his test.

This may be an isolated care, but be careful if this is the avenue you pursue and you have interest in testing the dog.

Good luck