The D7100 has a better AF system and a brighter viewfinder than the D5200. It also has more dedicated buttons allowing you to change settings on the fly without going into the camera menu.
BTW: When you get a few minutes please fill in your real first and last name.
The intent is to foster a community of "real people" instead of mysterious web personalities with anonymous screen names. Doing this helps to establish and maintain a safe, civil and friendly environment.