B8000 specs:
CONTRAST RATIO:4000:1
BRIGHTNESS(CD/M2):440
RESPONSE TIME(MS):8

https://shopee.co.th/HISENSE-55B8000UW-ULED...3054.2498467489

Malaysians see Hisense no up. Hisense also see Malaysia no up.

https://hisense.co.uk/tvs/all-tvs/?tv_features=uled

The U8B is said to have 1000 nits peak brightness.

I was thinking maybe B7xxxx --> U7x, B8xxx --> U8x. But don't know lah, Hisense is so confusing. lol.

Correct .
To sum it up , the UHD alliance standard requires TV with wide color gamut , to cover at the very least 90% of the colors from the DCI P3 color chart , which is what most HDR movies are mastered at .

Sony and Samsung , at the very least do make they adhere to the standards .
RU7400 , NU7400 , X7000G are all verified to reach 90% . 
Can't say the same for others and many Chinese brands though ( not going to name them before their legion of fans bomb my inbox) .

There is a local brand here which openly advertise their TV of having wider color gamut and their actual coverage is worse than LG'S entry model RGBW TVs .

Hisense thailand uses the word WCG on their B8000 TV. Not available in Malaysia.

If you compare the review for both tvs, yes x80g has slightly higher contrast than x85g (but both still below 1000:1) but x85g has higher peak brightness, so x85g will be better for HDR but wont be excellent. X85g has better picture processor so it can show more details like fine when viewed side by side with x80g. I'll upload a photo later.

Now u7a worth to buy?
65 only RM 3399 on shopee
if compare with ru7100

u7a does not even have dolby vision ?

but u said no good enough compare to entry level level of samsung, i also saw it at penang harneynorman, feel not bad for the quality.
u7a

Hisense really has big problem selling their TVs in Malaysia. 2017 model still selling here as their top end product.

I think it is because B7700 is a newer TV model. Hisense should bring in the B8000 which they are selling in Thailand. If they can sell that in Thailand, why not Malaysia ? It is just stupid for not offering the potential buyers an access to the B8000.

It could be Malaysia is the dumping ground for their leftover stock.

Quite noob in TV, just start researching weeks ago for new house.

Isnt it B7700 supported Dolby Vision.

I wonder which is more important, Dolby Vision that Netflix etc supported, or simply WCG

You mean 90% .

80%  you are still missing 20% of the DCI color palette .  And then moving on to some movies which are mastered at Rec.2020 , it is going to miss even more .
And WCG is only the first step , there is also color volume which is typically the strong point of Quantum Dots and very bright FALD TVs .
Every modern TV can call themselves a WCG TV thesedays because the modern basic 4K TV can cover 70-80% of DCI  chart which is still more than the traditional SDR TV which is only meant to fill up the old rec.709 .
I believed all the big TV brands (namely the big 4) have a certain standards to adhere to . So if they are saying their TV supported WCG , it means that tv can practically reach over 90% of DCI , or at the very least  close to the 90% set by UHD alliance .
For eg , LG has specifically mentioned their UM7600 covers a wider color gamut , except the 50 " model which will probably fall short of the 90% .
Dolby Vision is a type of HDR format , like HDR10+ , HDR10 , Technicolor and so on.

WCG being one of the hardware requirement to display vibrant , impactful and realistic HDR effects.

So to sum it up , TV of any spec with DV chip installed can theoretically play DV content  , but whether if the Dolby Vision will look as vibrant and as good it should , that will have to depend on the TV spec with WCG being one of the requirement .