The D5200 has excellent JPEG processing and a solid noise profile for its price class. It does a slightly better job at resolving detail as ISO sensitivity rises than does the Canon EOS Rebel T4i, thanks to its higher resolution, which seems to give it about a stop more latitude.
Below ISO 1600, shooting raw gives you some exposure-adjustment latitude, but no clear advantages for noise-reduction or sharpness. ISO 1600 marked the first level at which I could gain a little sharpness by processing the raw, but not without some tradeoffs on grain.
(1/30, f5, ISO 1600, matrix metering, AWB, 18-55mm lens at 34mm)
The D5200 renders excellent color, even those hard-to-reproduce pears. The Standard (default) Picture Style colors don't push the contrast or saturation very hard; I could barely see a difference between it and the Neutral profile, with the exception of boosted sharpness.