I think positive methods are great and many dogs can learn a lot that way. BUT, I can think of very few dogs I have met over many years that were truly reliable off-leash trained strictly PR. So - if you really do want a dog that can enjoy the freedom of running free, swimming etc. that should be a consideration. I think if my dogs were able to talk they would agree that the NR training they had was a small 'price' to pay for the freedom they now have!