Cathi...
Thanks. We're going to have to add '.NET survival guide expert' to your list of titles!
I think I'll try the 3rd approach (DataGridTextBoxColumn), as my prime need is to display descriptions in a grid from another table. It looks like they're using GetParent and ParentRow in their class to bring back the same kind of thing that I was looking for in an expression column.
Ironically, I pulled code from SyncFusion last month to deal with combo boxes in grids where the combobox needed to list descriptions from another table. So in retrospect, I probably should have done more research on applying it to a textbox. I think what discouraged me from going in that direction was that I couldn't find 'valuemember/displaymember' properties for a textbox.
Kevin