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. TCL 50S451-CA and Mi TV X50 are well-equipped smart TVs that aim to provide a balance of picture quality, performance, and smart capabilities. TCL 50S451-CA and Mi TV X50 differ in resolution (UHD vs 4K 3840 x 2160), which can affect overall clarity and sharpness of the display. Both TVs offer adequate brightness levels suitable for most indoor lighting conditions. In general, both TVs cater to modern entertainment needs, including streaming, gaming, and everyday viewing. Both TVs come in similar screen sizes, making them suitable for comparable viewing setups and room environments.

Verdict: Choosing between TCL 50S451-CA and Mi TV X50 depends on your usage, whether you prioritize display quality, smoother motion, or smart features.