>I've seen a number of admonisions against using
>FormSets, but no good indicator as to when they
>*should* be used.
>
>Does anyone have a good rule of thumb or a technical
>reason that FormSets help improve performance?
>
>TIA...
>
> ...kt

There is nothing bad in using formset, ... and nothing good too. It means that is not determinative for your application: it's possible to write good system with formsets and bad one without them and opposite will be also true.