TCL 85S451-CA and TCL 85Q9BK are two competitive smart TVs offering a mix of display performance, smart features, and overall value for different types of users. Both TVs come with smart platforms that support popular streaming apps and voice control features. TCL 85S451-CA and TCL 85Q9BK 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. TCL 85S451-CA and TCL 85Q9BK offer different motion rates (60 Hz vs 144 Hz), which can impact smoothness during fast-moving scenes like sports and gaming. Both TVs come in similar screen sizes, making them suitable for comparable viewing setups and room environments. Both TVs provide standard built-in audio performance suitable for regular usage, though external speakers can enhance the experience. In general, both TVs cater to modern entertainment needs, including streaming, gaming, and everyday viewing.

Verdict: Choosing between TCL 85S451-CA and TCL 85Q9BK depends on your usage, whether you prioritize display quality, smoother motion, or smart features.