As I just evaluate Kx as a companion to my beloved and often critisized K20D, I thought I might share a few results with you. As I was mostly interested in high ISO performance (on of the lesser strenghths of this model) and didn't like the results I saw from Kx initially due to its obvious NR influence, I directly deactivated it and shot RAW to see the images as straight from the cam as possible and viewed them in PS with prerelease Camera Raw 5.6 or whatever the verion is, that includes support for Kx. As I saw no relevant difference from the JPGs, the cam produced, I switched to JPGs with natural setting on both, K20D and Kx. I yet have to admit, that I left a color correction on in K20D where I tweaked color tone +1 to make red appear warmer and more natural in my eyes. But evaluating color wasn't my target anyway. To have both cams shoot at 6400, I set f-stop to 11 using an FA50 1.4 on both. Both were in Av-mode, although I had to give K20D an extra push of +2EV to achieve about the level of brightness of Kx. So actually K20D tends to underexpose under dim conditions heavily, what had been fixed in Kx. For what IMO is about the same level of high light rendering, K20D took 1/15th sec., Kx only 1/25th (yes, I ommitted using a tripod, hence the scene isn't exactly the same, which also might influence lighting). Kx rendered shades much better than K20D giving a wider DR, can see color where K20D just produces grayish grain. More convenient color rendition however seems to be easier with K20D, as it represents my view on the scene much better even with AWB whereas I chose warm white fluorescent tube on Kx.
I like K20D as it fits my hands perfectly. Furthermore, I very much like the fine grainy film like look all images from that model have even al lower ISO; wouldn't call that noise. For certain occasions, however, I would prefer Kx over K20D, because it is small and better in liw light. Initially I thought I could get along w/o it, now I feel I have to keep it.
Fotos attached named accordingly, complete diminished complete shot and crop.