Thanks for your support, the dxomark score does not take into account sharpness and resolution. It evaluates sensor on a noise/color point of view.
Basically the D5300/D5200 and D7100 achieve the same score on the DxOMark sensor rating. (1 point of difference means only 1/15 of a Stop)
To have the whole story, you should maybe wait for the lens result for Nikon D5300 (which should be available very soon).
The DxOMark team