As I mentioned in my previous post, I have yet to load the Pentax RAW files into Lightroom. I don't shoot jpeg, never have. My issue has been that my images straight out of the 645z have been a tad soft regardless of the selected aperture, shutter speed, ISO or the lighting (daylight, strobes). I was stumped about this and it wasn't until I looked at the metadata that I discovered one possible reason for the soft images.
When I shoot in Canon, I use the NEUTRAL picture style because it's rather flat and gives me more latitude when I futz with the color in Lightroom. On the Pentax I went to the Custom Image screen and found the Pentax Picture Styles (Portrait, Landscape, etc.) and selected NATURAL because it was the closest to a flat picture style that I prefer. So when I checked the setting on this picture style (Contrast, Saturation, Sharpness, etc.), I noticed that the Sharpness was set at -5. So I reset the sharpness to 0, and this gave me the edge to edge sharpness that I was looking for when shooting full-body shots. About the only time I pull down the sharpness in a picture style is when I'm shooting video because it lends to a more filmic look.
So for now, the camera is working for how I shoot, which is primarily, handheld.