My lab loves to pull, and the harness distributes the weight away from his neck whether he is helping pull the sled or just pulling me on skis. The fit is good on both dogs, and the harness seems very durable. They both squirm and try to get the harness off, but after only a half dozen outings they are happy to see the harness because it means a fun outing. My GSD was distressed by the training strap, and my lab prefers it without. In other words, both behaved and were happier without the training strap. I wish there was a quick release to get on and off easier.
Pulling-specific design comes in three sizes with four points of adjustability for a customized fit
Removable girth strap aids in training, and can be removed when dogs are accustomed to joring