TCL 58S455-CA and Mi TV X55 differ in resolution (UHD vs 4K 3840 x 2160), which can affect overall clarity and sharpness of the display. TCL 58S455-CA and Mi TV X55 are well-equipped smart TVs that aim to provide a balance of picture quality, performance, and smart capabilities. TCL 58S455-CA features a 58 Inch (147 cm) screen while Mi TV X55 comes with 55 Inch (139 cm), which can make a noticeable difference depending on your room size and viewing distance. Audio output differs between the two (10 W + 10 W vs 30 W), which can influence overall sound clarity and loudness. Both TVs provide decent motion handling, making them suitable for everyday viewing including sports and action content. Both TVs come with smart platforms that support popular streaming apps and voice control features. Both TVs offer adequate brightness levels suitable for most indoor lighting conditions. Overall, both models are capable choices in their segment, offering a balance between performance, features, and usability.

Verdict: Choosing between TCL 58S455-CA and Mi TV X55 depends on your usage, whether you prioritize display quality, smoother motion, or smart features.