Let me start by saying I am a combination trainer. I use positive and negative reinforcement. I use pinch collars and e-collars (for crittering), but I also use clicker training when corrections won't be particularly effecitve.
Strauss is a performance dog all around. Obedience, tracking, schutzhund, rally, agility, etc etc. There is very very little my Shepherd DOESN'T do. Heck, the only reason we don't do herding is because there's nobody in WI that does tending!
Agility is by far Strauss' favorite sport, followed closely by tracking. During agility, Strauss gets EXTREMELY wound up. He screams...like a banshee. When he gets going, he just can't seem to control himself. I would give him a command, he would decide I didn't give it fast enough, and he would come up and bite me. If my back was turned on him, he'd body slam me (the jerk).
I had tried scruffing him by the cheeks and telling him "NEIN! You DON'T BITE ME!" I tried quitting the game, I tried ignoring him. None of it was effective. I brought out my clicker, and I started clicking him for taking an obstacle and coming back to me. We worked up to a 5 chain sequence. Click treat for taking the obstacle and not biting. If he came back and bit, I dropped him, took him by the collar, and we went to the end of the line. He had to wait his turn.
In the following weeks, Strauss was ALWAYS put at the end of the line. He was consistently last. He was learning to wait his turn and focus on me. His focus has gotten a bajillion times better. The last three weeks of class, he has gotten frustrated and come back to me. Now he just jumps up in my face and barks. No biting. This would be intolerable to some, but I allow and accept it, because this is how he vents his frustrations. As long as he is not biting, he's allowed to show his frustration. Dogs aren't like people, and they don't bottle it up.
Strauss and I play tug when other dogs are running, because his prey drive is just too strong, and he can't focus while other dogs are running unless we're playing tuggy. He also continues to shriek like a cranky baby because he's not getting to run. Mouth full of tuggy = no sound froM Shepherd. Clicker training has been a very very big deal during our agility and obedience training. Now I'm using the clicker to reinforce his contacts, because he's blowing them right now, and is going to end up breaking a leg if he doesn't cut it out.
So, I've got a banshee screaming GSD that loves to work and would kill for agility. Used to bite like a landshark, and through clicker work, I've got him so he only bounces and "yells" at me. Improvement I think.