Originally posted by Byrd-2020 A 16 megapixel APSC sensor has larger photosites than a 24 megapixel APSC sensor. It will inherently have less noise. This is made less obvious by the image processor. However, it is, as I understand it, a simple law of physics that this is the case. It's always going to be a trade-off: Capacity for greater resolution vs lower noise. Everything is a compromise. Why do you think that the 16.2 megapixel sensor in the Nikon D4 (and now Df) has such tremendous high ISO capacity?
Ask yourself 'What are my photographic priorities?'. Maybe the K-5iis (the equal of the K-3 in most respects) would be the better choice.
This just isn't true. First of all, as technology improves, things get better. a K7 has significantly worse noise issues than a K5. Secondly, assuming the same technology, finer pixels gives finer, less obtrusive noise. The K3 is equivalent to the K5 with regard to high iso. DXO Mark basically gave them the same sports iso score of about 1200.
If you are talking about a per pixel level noise, you might be right. But who really cares about that. The assumption is that you will be viewing or printing the final image on the same size media, which will give an advantage to the camera with more pixels, in general.