In summary: The D7100 is a more robust, faster, and professionally-oriented camera built for reliability and speed. The D5300 offers a more user-friendly, connected experience with a flip screen in a lighter body, sacrificing advanced controls and build quality. Choose the D7100 for action, harsh conditions, or serious manual control. Choose the D5300 for travel, vlogging, and general use where connectivity and a flip screen are valuable.