The 55-inch smart LED TV Danay model K-55F3L11 has a 4k image resolution and its operating system is Android version 11. The viewing angle of this model is high and 178 degrees. The image brightness of the K-55F3L11 model is high, 320-350 nits, and its contrast ratio is 4000:1. This model has WiFi and supports HDR, and its panel is IPS technology.

 

a typical 55-inch TV is about 48 inches (121.9 cm) wide and 27 inches (68.6 cm) tall, with a diagonal screen size of 55 inches (139.7 cm).
A 55 inch LED TV provides a compact yet ample viewing area, perfect for medium-sized rooms. On the other hand, a 60-inch LED TV or larger is ideal for bigger spaces, offering a more immersive experience. Viewing distance: The optimal viewing distance varies with TV size.
You have said 2 TVs which are identical in every respect, calibrated the same, only difference being one is 50″ and one is 55″. There won't be any perceived difference in PQ. The pixel size in 55″ is larger but sitting at standard 6–8 feet viewing distance, you will not see it.