My practice is that ALL combo boxes are unbound and retrieves the row source On_Enter. That makes my forms load much faster. If you have a form with 10 comboboxes that all have to load data, the amount of loading that is necessary will give the form a huge performance hit especially if the user only uses one or two of the comboboxes.
Correct. Subforms, comboboxes & listboxes are "expensive" because they require a separate query in parallel to the form's recordsource. Looks like you've got it.