Thanks to all. Yes, I understand the LR3's NR is very good. That's why I said let's look at it as a more general case regarding plug-ins. I understand what's been said above, and I understand the workflow advantages of parametric editing, but still have the basic question:
In terms of flexibility, capability, range of adjustment, quality of results, etc., when changing things like color temp, exposure, curves, color balance, lens corrections, etc. are the results going to be the same (or at least comparable) when working on a tiff file as when working with raw? Or does working on a tiff file impose limits on what can be done to an image in LR or the quality of the output? Is the benefit to working with raw files in LR primarily workflow, or is there a benefit in terms of image quality, too?
If I apply a plug-in, from Nik or anyone else, create a tiff with the output of that plug-in, and then proceed to do more edits in LR3, will that impact what I can do with the image (not the workflow).
I'm not trying to justify not using raw files; I'm just trying to understand how LR3 works with non-raw files compared to raw.