The Nikon D5500 and Nikon D5500 features same sensor as of Nikon D7100, so you will get approx same image quality compared to Nikon D7100.
The Nikon D5500 Camera features advance image processor, the Expeed 4, but the new image processor doesn’t literally help the D5500 camera since the ISO speed, the continuous shooting speed and the video specifications remains almost same (although the Nikon D7100 have bit fast continuous shooting speed despite of having older generation of image processor.)
So it’s look like the Nikon has limited the functionality of the Expeed 4 image processor inside the Nikon D5500 camera.
Advance Autofocus System inside Nikon D7100
The Nikon D5500 features 39 distinct AF points, including nine cross-type sensors on the other hand the Nikon D7100 features professional-level DSLRs and comes with 51-point focus area with 15 cross-type sensors for detecting both vertical and horizontal variations.
If you are a sports shooter you must get Nikon D7100.
Introduction of the touch screen in D5500
The First Nikon DSLR with a Touch Display unit: Nikon D5500 comes with a large 3.2″ 1,037k-dot vari-angle touchscreen LCD monitor, which features a 180° swivel design, touchscreen functions allow you to pinch to zoom, navigate menus, choose settings, and choose your focus point.
Wireless Connectivity inside Nikon D5500: The Nikon D5500 features built-in WiFi connectivity, that helps you to transfer your images without any physical pain.
Other advantages of Nikon D7100: The Nikon D7100 includes bright viewfinder, weather sealed design and more battery life.
Verdict: Based on core specification we do recommend you to buy Nikon D7100 camera since it features advance core specification compared to Nikon D5500 DSLR and there is very less difference in the price tag of both the camera.
Also look at the Nikon D7100 Special Deal Page at Amazon