Overall, both models are capable choices in their segment, offering a balance between performance, features, and usability. If you're comparing Intex LED-3900 and Sansui SJX40HB21CAF, both models come with modern features and are designed to deliver a solid viewing experience across different use cases. Intex LED-3900 features a 39 Inch (99 cm) screen while Sansui SJX40HB21CAF comes with 40 Inch (102 cm), which can make a noticeable difference depending on your room size and viewing distance. 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. Intex LED-3900 and Sansui SJX40HB21CAF differ in resolution (1920 x 1080 vs 1366 x 768), which can affect overall clarity and sharpness of the display. Both TVs provide standard built-in audio performance suitable for regular usage, though external speakers can enhance the experience. Both TVs provide decent motion handling, making them suitable for everyday viewing including sports and action content.

Verdict: Both models offer good value, and the better option depends on your specific requirements and viewing preferences.