The weight is basically the relative mass of the constrained point. It determines how the component participates in the constraint. If the weight is zero then that point will get pulled but not pull back. In terms of the constraint it would be as if the other object was a passive object. (if the other object were in fact a passive object then the weight would always be as if it was zero)

At any rate the weight controls the relative participation in the constraint and in general is a specialized attribute that would be infrequently used.

The strength attribute would be much more commonly used than the weight. It scales the constraint strength. If it is zero then the link will have no effect and if it is 1.0 the link will have the stength defined on the constraint node.

In a sense the weight is a true nComponent attribute while the strength is really a constraint attribute. However the constraint node does not have a sense of surface the way the nComponent does, so we needed to put a strength scaling attribute on the nComponent node in order for this to be paintable.