Panasonic TH-65MX660DX and Samsung UA65U8100FULXL are well-equipped smart TVs that aim to provide a balance of picture quality, performance, and smart capabilities. Both TVs provide standard built-in audio performance suitable for regular usage, though external speakers can enhance the experience. Overall, both models are capable choices in their segment, offering a balance between performance, features, and usability. Both TVs offer adequate brightness levels suitable for most indoor lighting conditions. Both TVs come in similar screen sizes, making them suitable for comparable viewing setups and room environments. Both TVs provide decent motion handling, making them suitable for everyday viewing including sports and action content. Panasonic TH-65MX660DX and Samsung UA65U8100FULXL differ in resolution (4K vs 4K 3840 x 2160), which can affect overall clarity and sharpness of the display. Both TVs come with smart platforms that support popular streaming apps and voice control features.

Verdict: Choosing between Panasonic TH-65MX660DX and Samsung UA65U8100FULXL depends on your usage, whether you prioritize display quality, smoother motion, or smart features.