Launched in the year 2021, the 75U90G is a 75" 8K TV from Hisense. It comes with a 10-bit IPS panel with Anti-glare/Matte finish. The maximum resolution it can display is 7680 x 4320 @ 60 Hz with a pixel density of 118 ppi.
Picture Quality
Now, the very next spec of a display that defines picture quality is its Color Gamut.
This TV doesn't come with a color gamut specification, but don't worry, we have other means to guess that.
Now, since the TV features a big 75 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! It is capable of producing accurate colors by default.
Understanding Color Gamut
Color gamut specification of a TV is the measurement of the range of colors that the TV can produce.
A TV with poor color reproduction will produce washed out colors that will spoil your immersive experience.
It is specified in different units - sRGB,sRGB (standard RGB), NTSC 1953, DCI P3 etc. It is upto the manufacturer which one they choose.
But you don't need to worry about that, here is a chart that will help you choosing a TV with good color accuracy.
Now, next in the list of important specifications is Static Contrast.
Understanding the static contrast ratio of a TV
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.
This tells the intensity of black levels. That is, a TV with static contrast ratio < 1000:1 may produce black images something like this:

Moreover, such TVs are likely to suffer from backlight bleeds that will impact your experience — as shown below.

Static contrast ratio and resolution go hand in hand when it comes to details. To put it into perspective, a TV with low contrast ratio will produce less shades of colors, thus lesser detail overall.
If given a choice, always prefer a FHD TV with high contrast ratio over a 4K TV with low contrast ratio.
This TV comes with a static contrast ratio of 10000:1., good enough to produce deep blacks. The panel comes with local dimming feature which is a plus.
Dolby Vision, HDR10, HLG (Hybrid Log Gamma) and HDR10+ are also supported on this TV.
Coming to brightness, it can go as bright as 2000 nits with the help of Mini LED backlight. This amount of brightness is good enough even for a room with sun's rays in!
Gaming Performance
Now if you are going to use your TV other than watching videos — say as a PC monitor or Gaming, make sure to take a TV with lowest input lag. For gaming, both input lag and response time affects the performance.
Unfortunately, there is no specification for input lag on this TV. Now, since this is not a cheap TV from Hisense, we can expect an input lag of less than 20ms.
What is Input lag ?
This lag is the amount of time at which your key-presses/mouse movements changes the content of your display. Though, this won't matter much if you aren't into competitive/FPS games like call of duty.
But ideally, get a TV that features an input lag and response time of less than 20ms.
Ergonomics and Dimensions
Now, coming to 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 600 x 400 mm. The unit doesn't come with either Swivel, Tilt or Pivot support.
Vertically, the TV measures 75 inches and horizontally 65.98 inches.
Coming to thickness, it is just 2.64 inches thick. It weighs 52.9 KGs and 3.1 kgs extra including stand.
Hardware and Audio
The Hisense 75U90G is powered by 4-Core CPU. However, Hisense didn't provide any info about the total available RAM on the TV's specsheet.
The Operating System on this TV is Android 10.
For display connectivity, there are two HDMI 2.0 (CEC) ports, one AV Composite In (Video + L/R) port and two HDMI 2.1 ports on this TV.
To connect USB devices, it includes — 1x USB 2.0 and 1x USB 3.0. Other connectivity ports include — 1x Cable/Antenna In (F-type) and 1x Ethernet RJ45.
For connecting to this TV wirelessly, the manufacturer has provided a 5Ghz Wi-Fi, 2.5 Ghz Wi-Fi, Wifi-Direct and Bluetooth 5.0.
Coming to audio, Hisense has provided 2 x 15W speakers on the 75U90G. It also comes with a built-in sub-woofer. So you don't have to invest on any external sound system.
As for power consumption, on average, it consumes about 157.2 Watts and on standby, it takes 0.5 Watts.
For powering this unit, you'll require an 100 V - 120 V/50 Hz - 60 Hz outlet.