In your original post, you sum up well the pros and cons of the K-7 and K-r. The K-7 is WR, has an excellent viewfinder, excellent body and grip, semi-pro functions. The K-r has excellent high-ISO performances.
I feel however that the discussion and your toughts might be biased by High ISO versus low light performances. Unless you want to shoot especially at high ISO (eg for grainy appearance of the photo), most users are interested in low light performances.
I have had the K-7 for one year and there are several ways to have excellent low-light performances with the K-7. These include:
- with some in-camera PP, it is possible to get very nice shots either with in-camera PP (see
K-7 High ISO Success!)
- with some dedicated noise reduction software like Noiseware and NoiseNinja;
- with some fast prime lens.
I have used all the above techniques successfully, although I prefer the latter in the darkest conditions. The first two techniques are very easy to use and implement. However, in dark conditions, my preference is a large aperture (f1.4) prime lens with MF. I got my best results with my Voigtlander Nokton 58mm f1.4 MF.
Again note I do not talk of high ISO, but real low-light conditions. You should do the same
Let me add, lastly, one more bit of advice: go to your local store to try yourself the K-r and K-7. Your hand feel is most important. Some people with large hands do not like the K-r (too small). Ultimately, it's you who will use the camera and you do not want to be disappointed.
Hope that the comment will help...