Interesting... that clarifys my misunderstanding of 1-Default Data Session. I thought it referred to the public datasession. Still, don't you have to:

1. have some sort of form handling mechanism to determine which child forms are instantiated and close them when parent is closed.
2. prevent user from launching same child form twice.
3. constantly check if child/parent exists if you need to update related form objects from a related form's logic.

These (and some I haven't thought of yet) are not relevant when using formsets. I'm still interested in hearing why formsets are discouraged.

Thanks,
Jeff