Hello Bob & Danny,
The single most important thing, as you'd know, is to minimise any quality loss caused my editing, saving, re-editing images. It's mainly with lossy formats like JPEG where this is a problem.
If you shoot in RAW format and maintain that throughout your editing (whatever software you're using), till the final export, you're doing just that. Much easier to edit an image where some of the data hasn't already been thrown out!
If you shoot RAW & think RAW right up till the final export stage, that lets some software fall by the wayside. I do think it's good to compare the impact on image quality of processing in various pieces of software. I'm not aware of any such research.
Part of my workflow, when I need to use specific filters or plug-ins in other software, is to duplicate & rename image files. Each of us, I guess, would have their own ways of going about things. I'd be interested to hear about workflow ideas that work for you.
Again, when using "external" editors, I retain the original format where possible. True - not always possible.
I'm certainly no expert on Digital Asset Management (DAM), but I'm learning!
Like you, Bob, I'm having a lot of fun turning some (admittedly) pretty ordinary photography into images that make people stop & look!
PIX
P.S. I wouldn't count on the Z**er product (FREE) handling your RAW files
http://free.zoner.com/products.asp
PIX YouTube channel