I am SO excited for you. It's such a fantastic feeling when your dogs are doing what you want them to do and behaving properly. And even better, without being dominant over them or breaking their spirit in any way!
I know how badly you have been wanting this and I'm just so thrilled you found such a great trainer. It sounds like he really knows what he is doing and that Max and Cooper are learning!
Maybe after this you can get Max involved in agility (I think I remember you saying Max was the one who was really enjoying what you had made in the back yard). Self control is such an amazing thing when they learn it.
Go Cooper and Max -- and GO Karen! You guys make a fantastic team and I can't wait to hear more about how it goes!