I totally agree with the above. Some of the best dogs I have ever had have been mutts. Dogs are not machines and even getting a puppy and raising it does not guarantee it will do everything you want it to.
I somehow ended up with a pure bred through a rescue. My cairn terrier is such an amazing dog. She's smart, loyal and active. And she's freaking bullet proof. Just a tough little dog. She's the kind of dog I know I could take hiking and camping if I wanted to. But I also know that not all cairns are like her. It's all in the individual.
I also want to add if you do decide on a certain breed, consider a rescue. Rescuing an adult dog is awesome. Most times they are out of their chewing stage, fully house broken and already use to the coming and going of living in a home. Dogs are not always given up due to bad behavior. Sometimes people move or have babies and the dog is given up then. I have been rescuing for years and it's very rewarding.