I am currently investigating the top-down design methods. I have actually tried an approach where I define an assembly sketch and the parts are created in the context with references to the sketch. This methods works fine and the workflow is clean. I can even put sketch entities in blocs in order to do a simple motion simulation.
Now, as I feel all of this working fine, I was wondering why the layout sketches were needed? Is there an added value in them? I guess there is, but I cannot figure it out, it is not obvious to me. Any idea?