
Several people I know have bought the harnesses and say they have been an enormous help.
When you walk and then stop, do you continue to walk the same way? If so, what is happening is he is expecting to carry on. When I train my lot, they have to keep watching me as they never know which way I am going to go.
One lady I helped with a similar problem I discovered always left her house and turned right to go immediately to the fields. She would walk, then when the dog pulled stop. Simply by getting her to set out and turn left and walk in that direction even if it was only a 100 yards or so helped break part of the habit this dog had developed. When out walking, I got her to stop when the dog started pulling. Once the dog was calm instead of going on in the same direction all the time, I got her to walk in a different direction even retracing her steps. Walks take a lot longer but it achieved the end she wanted.
When you see birds do you tell him to leave it in a very firm voice? I'd try this and make him sit, then move on once he is calm or just to keep his attention on me by moving in another direction. When he is good and walking nicely, very quietly, talk to him, I have found dogs will look at you, when you very quietly talk to them. I tell my youngsters they are good and I do quietly say heel but only when they are at heel. I will slip them an occasional treat if they are at heel when I say it, which gives them extra incentive to concentrate on me. Eventually they learn. How old is your dog? Is he a rescue or have you had him since a puppy?