Mike Blume , Apr 29, 2009; 03:17 p.m.
First, if you save the original DNG files, you can always go back and re-edit if the need arises. Second, I can think of no reason to save final edits as TIFF files. They are large and if re-editing is desired they are not ideally suited to this purpose. If I wish to save a file with my editing work intact (layers, adjustments), I use the .psd format.