It's impressive that the K3 can do as well as it seems to here, but I don't think these images support their conclusions. Rather, they confirm what anyone who has used fairly recent Nikon cameras probably knows - that for similar settings Nikons tend to overexpose compared to other cameras (I learned that with my first dslr, a D3100, but I've seen the same thing on the D600 and D800e I've rented; my father always has the exposure compensation on his D7000 set at least at -0.3). I suspect that if you reduced the exposure a bit in LR or some other software the Nikon images would look at least as contrasty, colorful etc. as the Pentax ones. And if you look carefully at the photo of the barbed wire fence, you will see that while one of the barbs in the Nikon image is more-or-less in focus (I assumed that's what they focused on), it isn't in the Pentax image (nor is anything else, quite). I have no idea why; maybe it's user error, or maybe it's a reflection of what those of us who have owned Pentax cameras/lenses know - whatever other virtues they may have (remarkable DR being chief among them, probably), focus speed/accuracy isn't one of them. Some of the images also reflect the Pentax tendency to boost blues; look at the spruce tree shot, for instance (I once took a photo of a patch of dark purple petunias with my K5; in the resulting photo they were pure dark blue...).
