I also was kind of looking at the e-collar. My 9 month old bullmastiff pup likes to test me, which I think is normal. But the problem sometimes is when he doesn't have his prong collar or lead on. For example -- If he happens to have something I don't want him to have and I tell him to drop it -- If he has his prong collar on he will, but if not he will want to test me and try to play keep away. I don't let him win, I eventually get a hold of him and put his prong collar on. At that time he is an angel because he knows he is in trouble. We will go through a series of commands until he is listening to everything I say. Would this type of situation be a time for the e-collar? or should I just keep being persistent and not let him get away with that kind of stuff?