We have only used R+ with out dog and trainer. I have heard that any aversive training can make the dog more reactive which we certainly do not want. I would think that when a dog growls at someone and you use and e-collar it learns to stop growling and just goes to biting...I am not sure if I understand that correctly however it would make sense NOT to use an e-collar for reactivity. However what about behaviors that arent reactive, super problematic. For example, the dog jumps up, or the dog gets close to the cat. Why would using an e-collar in these cases make the dog worse? I am not going to be using a e-collar but I was just curious about the explanation behind that. Thank you!!