The XR-55X90K NA is a 55 inch 4K TV from Sony. It was launched in 2022. It features a True 10-bit VA panel. The maximum resolution it can display is 3840 x 2160 @ 120 Hz with a pixel density of 80 ppi.
Picture Quality
After screen size and resolution, the next important spec to look for in a display is its Color Reproduction Accuracy (defined by its color gamut specification).
This TV doesn't provide a color gamut specification, so we have to take a guess. Now, since the TV features a big 55 inch screen, it won't come with a cheap panel, so here we can assume its equivalent sRGB coverage to be 90-100% or above. Undoubtedly The color accuracy on this TV should be Lifelike! Meaning it is capable of producing accurate colors out of the box.
What Color Gamut means ?
Color gamut specification of a display is a measure of the range of colors that the TV can display.
A display with poor color reproduction will produce washed out colors that will spoil your immersive experience.
Different manufacturers use different measurement standards to specify color gamut. Viz — sRGB (most popular), NTSC 1953, DCI P3 to name a few.
But don't worry, below is a chart that you can use to choose a TV with good color accuracy.
Now, after color gamut, the static contrast ratio of a TV holds almost equal role in picture quality.
What is Static Contrast ?
There are two types of contrast specifications for a TV. Static and Dynamic. We are interested in static contrast ratio. Dynamic doesn't matter much.
Static contrast specification defines the intensity of black levels. That is, a TV with static contrast ratio less than 1000:1 will produce black images something like this:

Apart from that, such TVs may suffer from backlight bleeds that will impact your experience — as shown below.

Like resolution, the static contrast ratio is also equally responsible for details. To put it into perspective, a TV with low contrast ratio will show both dark gray and black as black, thus lesser detail overall.
This TV is rated with a static contrast ratio of 8000:1., good enough to produce deep blacks. For the record, it also comes with local dimming backlight technology which is a plus.
HDR is also supported on this TV in form of Dolby Vision, HDR10 and HLG (Hybrid Log Gamma).
Coming to brightness, the peak luminance the TV can produce is 250 nits, powered by Direct LED (Full-Array Local Dimming) backlight.
Gaming Performance
If you are planning to use your TV just for content consumption, you can safely ignore these specifications. But if you are also going to use the TV for playing games or use it as a PC monitor, make sure to get a TV with the lowest input lag and response time.
Unfortunately, we cannot find the input lag specification for this unit. But since this is not a cheap TV from Sony, input lag on this TV could be 20ms or below.
What is Input lag ?
This lag is the amount of time at which inputs changes the content of the screen. Though, this won't matter much if you aren't into competitive/FPS games like call of duty.
But ideally, look for a TV that has an input lag and response time of < 20ms.
Dimensions and Ergonomics
The TV extends upto 55 inches (adjustable +1.57 inches) vertically and 48.54 inches horizontally.
It is just 2.83 inches thick.
Overall the TV weighs approximately 18.5 kgs including its stand. Without stand, it weighs 17.4 Kgs. So plan your space accordingly.
Speaking of ergonomics — If you plan to wall mount the TV, you can make use of the VESA mount provided with this TV, which by the way has an interface size of 300 x 300 mm. The unit doesn't come with either Swivel, Tilt or Pivot support.
Hardware and Audio
The internals of Sony XR-55X90K NA is powered by a Quad Core CPU. However, we could'nt find any information about the total RAM on the TV's specsheet.
For display connectivity, there are four HDMI 2.1 ports and one AV Composite In 3.5 mm jack port on this TV.
To connect USB devices, it includes two USB ports. Other connectivity ports include — 1x Cable/Antenna In (F-type female), 1x RS232 (C) and 1x Ethernet RJ45.
Wireless connectivity options on this TV include a 5Ghz Wi-Fi, 2.5 Ghz Wi-Fi, Wifi-Direct, Bluetooth and DLNA.
Now, speaking of speakers, Sony has provided 2 x 10W speakers on the TV.
Speaking of power consumption, on average, this TV consumes around 113.28 watts. On standby, it uses 0.5 watts.
Both 110V and 220V lines are supported on this unit.