Audio output differs between the two (10 W + 10 W vs 2 X 10 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 in similar screen sizes, making them suitable for comparable viewing setups and room environments. TCL 43S451-CA and Mi Xiaomi TV A 43 FHD 2026 differ in resolution (UHD vs 1920 x 1080), which can affect overall clarity and sharpness of the display. Overall, both models are capable choices in their segment, offering a balance between performance, features, and usability. 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. If you're comparing TCL 43S451-CA and Mi Xiaomi TV A 43 FHD 2026, both models come with modern features and are designed to deliver a solid viewing experience across different use cases.

Verdict: Both TVs are strong contenders, and your final choice should depend on your preference for screen size, motion performance, and smart features.