Hi, yeah it's me droning on again,
I am so glad your puppy is showing some improvement.
My concerns are really about the age of your pup. At six months old he should have no idea that he has any possibility of being "dog enough" to bite people. He is also very young and immature to handle the stress and level of training required to control and modify his behaviour.
I think the stratagies you are already employing are very useful but if you can anticipate a bite situation you MUST intervene before it happens. Every bite your dog makes lowers his already very poor inhibitions toward people. The intervention should be quick, strong and of a nature that the dog will have trouble forgetting. For a six month old puppy this is tough going.
In this situation it is impossible to give specific remote advice as the age of the pup and the nature of the problem presents a fine balance.
The fact that the pup will drop ( I am assuming you mean down?) on command is encouraging, practice this everywhere. Give rewards for calm behaviour when passing people and when allowing people to pass him.
Does he get to free run anywhere? If not it may be worth while finding a safe place to let him run free. It may help him relieve his frustrations and stress. Apart from that all dogs need dog time off the lead to do their own thing.
One last thought, Shepherds can be encouraged to become obsessed by a toy and this may help in rewarding him, distracting him and focusing his full attention on you.
Good luck and please let us know how you are getting on.

[This message has been edited by carrie (edited November 03, 2000).]