Matt,
We have been using WDDX to store form data in the data base
for a long time. I would say that storing it in XML is a better
route because most databases (SQL Server and Oracle is what I have
the most experience with) do have the capability to rip through XML
using X-path, etc. The best way though, that we have found out is
to have a "Properties" table. So it has a "PropertyName" column, a
"PropertyValue" column, a unique ID, and a Foreign Key ID to say a
"Report" table that is storing the form (config) data for. So then
you would query the "Properties" table, and get all the needed
values from it, and then do whatever it is you need to do in your
code based on those values.
Having a "Properties" table leverages itself way better to
reporting on the properties, where you can write a query to get
that information instead of having CF to dump that information.
Hope this helps.
Johann