Don, I shoot JPEGS and with the GRD4 use the image settings for my processing.
The interesting thing about this is it encourages you to get exposure right.
Often I can be relying on PP as a method to correct my laziness in the original exposure.
It seems we are starting to see a few cameras with good in camera processing. The new Fuji X1-Pro is being lauded as having great jpgs.
I think the GRD IV can join that club. There is a lot of in camera tweaking for the GXR as well.