One observation I have made, the Nikon might seem less sturdy, but the quality control seems better. The inbuilt horizon level is accurate, the lenses I have (admittedly all Nikon) seem to focus pretty accurately as well. The pentax Kx and K5 needed major adjustment through hacking the OS to get all my lenses to focus within the user adjustable range. The Pentax needed the most adjustment. That is just shoddy, I did not want to buy another camera with a wonky horizon level or one where the af adjustment range was not enough to get it spot on.
Pretty much anyway. I have been out and about with the K5 and the D7100 to see how the results compare in similar typical shooting conditions. Despite comparing 16/24 megapixel, the increased image size is really not so obvious. On the Nikon I only have the 10-24 at the moment, so I was out with just the 10-20 Sigma this evening. I do like the SWM focus on the Nikon. It is quieter, seems to settle onto focus without jiggling back and forth and seems to be consistent and accurate. I am even getting used to what I can see in the viewfinder. I can see the virtual horizon and my ISO now, which I had not worked out last time I had a D7100.
I am not so keen on only having 2 user modes and that buffer is a disgrace. Are you listening Nikon? Hang your heads in mean and miserly shame. At least with the Sandisk 95mb/s card it is able to chug along at a reasonable rate, but I have been spoiled with the Pentax, which does not rely on expensive memory cards to make it responsive and just seems to machine gun shots till you get bored with holding your finger down. I am also not that impressed with the build quality on the Nikon. The memory card door feels quite flimsy and there is no way it would keep damp breath out. let alone a light drizzle. I have never relied on weather resistance, so I guess it is a moot point. Maybe the Scotland trip later in the year will help galvanise my opinion on this.
I have picked up a wired timer remote already, but I guess I need to collect a few little do-dads to flesh out the Nikon system. Next purchase is the 18-140 and then maybe a 35mm f1.8 or (more useful but more expensive) the Sigma 105mm OS macro. And time to start thinking about selling some of the Pentax gear to recoup the cost.
Nothing too rash yet though!