One of the problems whenever any new camera is released is that the internet is alive with reported problems about the camera. Most of them are simply reflective of not spending enough time getting to learn the new camera before blaming it for what turns out to be unintentional user error.
Be aware that the extra resolution and pixel density when used right will produce sharper more detailed photos, however it also is less forgiving of errors like camera shake. If you use good technique and don't try and hand hold shots at way under acceptable shutter speeds you will be fine.
The d7k is the best DX camera on the market right now, and can even play in high ISO situations with some of the FX big boys for way less money. I have been very happy with mine and I have not had any problems with it whatsoever.
p.s. For comparisons, I am far from a pro or expert photographer, photography is a casual and beloved hobby for me.