Panasonic TH-58HX450 and Samsung HG55AT670UJ offer different motion rates (60 Hz vs 100 Hz), which can impact smoothness during fast-moving scenes like sports and gaming. Panasonic TH-58HX450 and Samsung HG55AT670UJ are two competitive smart TVs offering a mix of display performance, smart features, and overall value for different types of users. Both TVs offer adequate brightness levels suitable for most indoor lighting conditions. Both TVs provide standard built-in audio performance suitable for regular usage, though external speakers can enhance the experience. Both TVs come with smart platforms that support popular streaming apps and voice control features. Both models support 4K 3840 x 2160 resolution, ensuring sharp picture quality with detailed visuals for movies, shows, and gaming. Overall, both models are capable choices in their segment, offering a balance between performance, features, and usability. There is a difference in screen size (58 Inch (147 cm) vs 55 Inch (139 cm)), and a larger screen generally provides a more immersive viewing experience.

Verdict: Both models offer good value, and the better option depends on your specific requirements and viewing preferences.