TCL 43S5400 features a 43 Inch (109.22 cm) screen while Haier H40K85EFX comes with 40 Inch (102 cm), which can make a noticeable difference depending on your room size and viewing distance. TCL 43S5400 and Haier H40K85EFX are well-equipped smart TVs that aim to provide a balance of picture quality, performance, and smart capabilities. 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 models support 1920 x 1080 resolution, ensuring sharp picture quality with detailed visuals for movies, shows, and gaming. 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 TVs provide decent motion handling, making them suitable for everyday viewing including sports and action content.

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