DPP: RAW tone curve and "Linear"-option

Hey all. In Digital Photo Professional, right under the tone curve of the RAW-tools page 1, we have an option to either tweak the 9-step slider, or choose the "Linear"-option instead. I've been wondering and trying out this setting recently.

Choosing it makes the image more dim, which I think looks interesting for certain subjects, and you can bring the brightness back to normal levels by using the RGB curve and clipping controls on the next page of the tool palette. The images seem to end up looking fine even if edited this way, just a little different.

A few questions though: the DPP help file didn't explain much of this setting, and mentioned that it is helpful for checking the image for possible problems, so:
-what does it do exactly and how is it different?
-does using this setting degrade the image quality in any way? (it's a RAW-file, so I think it shouldn't)
-is it this setting the best option for this kind of edit or is there any better alternative?

And it seems to me that using the normal tone curve, with any slider setting, clips the shadows/highlights a bit more than when using the linear-option. Well, I'd like to hear you input - I might be using this more in the future.

Thanks for reading.

When you check that Linear box, you are basically telling DPP not to apply any tone curve to it so what you see is exactly what was captured by the sensor (after the Bayer pattern processing, of course, to bring back the colors). If you want to apply your own tone curve to the image, this is the best way to process the raw image, which is basically what you did when you checked that option and then went into the RGB palette and adjusted the tone curve to your liking.

Thanks for your reply, that's pretty much how I saw it too. How about one more thought: previously I had been moving the slider setting all the way left for the least contrast and least blown highlights (and then customizing the curves) - even though it saves the highlights more, the contrast seems to be (at first) much less than with the linear-option. One might think the when the slider is moved to left, the tone curve would become more straight, i.e. more linear-like, but apparently that is not exactly true?

Of course, one of the differences is still the histogram on the next page being more compressed to the shadow side. (although I don't exactly understand the reason for this effect - other than that the setting was supposed to be just a quick checking tool, maybe.)