Originally Posted by Oblada

Thats true but I dont agree completely with your example;

Lead walking is usually as or more tiring (more mentally stimulating - if done properly of course!) than off lead unless the off lead is composed mostly of exercises/training etc.
A lot of people allow "uncontrolled" off lead, which really does not do a lot for the dog.
I personally believe that lead walking is an important part of a dog's life, it reinforces the bond with the owner...much more than dropping the dog in a field and letting it be for whatever length of time (which I see lots of people doing in my area...)... But of course off lead can also be used very beneficially, doing recall, retrieving, searching etc!