It seems everyone in Pentax land is getting excited about noise performance of K-5 and K-r - two most recent and most up to date offerings from Pentax. It goes without argument that noise performance of K-5 has improved significantly on K-7. However K-7 is no slouch. At this moment I see no particularly strong reason to shell yet another 4 figures in USD for the new camera. Rather, I bought Topaz Denoise for approximately 1/20th of the price of brand new K-5. Here is a picture I took not long ago and processed it with Topaz Denoise. It was shot at ISO 1600, f/2.5, 1/50 sec with FA 77/1.8 Limited.
Two 100% crops for your inspection:
It seems to me that I can actually shoot safely at ISO 3200 now, although previously I limited auto ISO to ISO 1600. Of course this is not wondrous ISO 25600 or even ISO 51200 of K-5, but it will satisfy my needs quite nicely.