I've been researching breeds a lot (still leaning strongly towards American cocker spaniels, but definitely not 100% settled on them yet), but I have one pretty big question after all my research. I'm not sure exactly how to phrase it, but I'll try. How much, exactly, does going to a good breeder "guarantee" that you'll get a healthy pup with the temperament its breed should have? For example, the breeder health tests for all the breed's major issues and selects parents based on their temperaments, the puppies are raised in the house as members of the family and socialized by the breeder--what are the odds of the puppy being happy and well-adjusted? Is it still going to be a big gamble?