Sorry if this has been posted previously. I was just reading the ephotozine review of the K-x, was amazed by the low noise at 6400, and pulled up the 5Dm2/D700 reviews for comparison:

K-x:

http://www.ephotozine.com/articles/pentax-k-x-hands-on-preview-12172/images/pentax_kx_iso6400.jpg;

5Dm2:

http://www.ephotozine.com/articles/Canon-EOS-5D-MkII-10262/images/canon_eos_5d_mk2_iso6400.jpg;

D700:

http://www.ephotozine.com/articles/Nikon-D700-9795/images/Nikon_d700_iso6400.jpg;

Clearly, the FF cameras have a lot more detail at 1:1, but it might be partially related to the review lens or default sharpening on the K-x, as even the ISO-200 image doesn't look quite as sharp as the canon or nikon:

http://www.ephotozine.com/articles/pentax-k-x-hands-on-preview-12172/images/pentax_kx_iso200.jpg;

Regardless, the fact that the K-x is even approaching a remotely similar high-iso ballpark to the two $2500+ noise kings, under any conditions, is incredible to me. I expected something more like what I found in the K7 review:

http://www.ephotozine.com/articles/pentax-k-7-11613/images/pentax_k7_final_iso6400.jpg;

Granted, these are all (I assume) shot from default jpeg, with all the caveats and uncertainties therein. But as even a vague idea of what I might get from raw, I'm impressed. Looks like about two stops of usability over my k100ds (eyeball estimate). Shooting up to 3200 where I currently shoot 800.. man.. that would be fantastic.