So we have a five month old Boxer, and we started using this harness about two weeks back. Before this we were using the Martingale collar (again by Alcott). With the Martingale he was getting better at his walks, but the progress was pretty slow and the effort needed was a lot. Using this harness was almost like suddenly we had a new mature dog who knew his stuff already! So it's truly made a difference. Yes, he still has his moments of madness when he comes across a cow or a pig or something new that he isn't used to - but life (and his walks) have become a breeze.