The picture quality gap between this 2 models is like point gap between Liverpool and Manchester United.
If 55" just nice for you seating distance, go for Pana.

FYI, B7700 doesn't have WCG panel to display HDR colours.

Hey, u got ur TV already? That's fast.

how is the tv bro in term of performance, clarity but I hear it support dolby vision and atmos and more over got usb 3.0? how much you bought this tv and where?

It doesn't , none of the GX800 variant has local dimming .
What you are noticing has nothing to do with local dimming but the backlight system of the TV .

This is an edge-lit TV , which tend to demonstrate many of the flaws you mentioned above in a dim/dark viewing room . Also the fact that it has an IPS screen (which means it has a poor contrast ) doesn't help either .
IPS TV are typically recommended in a decently lit room because human eyes can hardly notice the changes on black level when there are ambient light sources around .
There are several new Full Array Local Dimming TV models landing in Malaysia this year , ranging the very anticipated Sony X90H to Samsung's Q80T and Q95T  , all models will be available from size 55 " and above for the first time in MY.
I predict there will be a significant price drop compare to last year .
They are both mid-range TV , except Samsung likes to overhype on their Quantum Dots displays when they can barely utilize its benefits .
The GX800 is compatible with Dolby Vision though so that is a plus .

The 49" Q60R is also kind of crappy since it was downgraded to 60 hz .

No , there is no fact here . The TV just doesn't has local dimming .

I think you are confused , because you see a few " columns " that lights up you are thinking it is local dimming because you have been reading some of those FALD TV has "zones " .
These are completely different things .
It is similar to what Hisense called their TV having 2 zones , 6 zones .
Those are not local dimming system , they are software based algorithm used to restrict the APL and they are not effective at all .
They can give them whatever name they have , commonly known as global dimming , frame dimming , etc etc . They don't improve picture quality.
Localized dimming system , need to do 2 things . 

First , is to dim the black levels to improve contrast and thus also improving picture quality .

Second , to boost the Highlight of brighter portion of objects objects to improve the Dynamic Range of the picture .

A Full Array Local Dimming can do both , an Edge-lit based Local dimming TV can only brighten the picture .
We have had great Edge-lit local dimming TV before , like the Samsung NU8000 which can boost brightness up to almost 1000 cd/m .  GX800 does neither of this .

Also GX800 models have an edge-lit based backlight system ( not to be confused with local dimming ) , even if it has local dimming it wouldn't show up in "zones " .
Remember , the models shipped in our country is the IPS variant , it is different than most of the GX800 reviews you read from the internet.

How is this tv performance for 4k movies, it is still need android box like Himedia?

May I know this tv is what energy stars ratings  4 or 5?

Is this tv can same performance like sony x70 or x80 series?

1) Actually not yet buy the tv first plan to buy Sharp BK1X but somehow i found this panasonic tv got this dolby vision/atmos and also got usb 3.0?????

3) When you bought this tv, how many years in the warranty and support? till now did you got any problem using tv in term any broken parts? How many inch is this tv you bought?

1) may i know why u said when i downlaod movies cannot get dolby vision?

3) oooh u recently bought this tv may I know what is the mean of "uneven backlight or light leaks" can you give the screenshot

what is your tv inch?

bro what different between gx740 and gx800 and what u mean for normal consumer???????????/

Not really , not every LED TV has light bleeds , mostly only the edge-lit TV models and IPS TVs due to the imperfect shapes of subpixels .

At the very least , learn to differentiate the Pros and Cons of IPS &VA TV first before you start giving advice . 
What's wrong with being technical in a techie forum ?  If you just want to trash talk your way to the end , there is the /k section.
Another assumption from you .

The GX800 is already at baseline 300 nits . If we go with your logics , the GX740 has to be even dimmer than every other modern TV , including those beginners 4K models from other brands .
You need to stop reading into whatever terms the TV brands are throwing at you . At this point you are only spreading wrong information .
True , but there is a huge difference between local dimming or simply calling it a dimming system . 
First of all , there is no story . I have spent roughly 2 hours with the TV beside NU8000 , which an edge-lit local dimming TV . 
It doesn't dim nor boost , it does nothing , absolutely no changes on the black levels and brightness .

Localized Dimming system is specific hardware that is implemented on the LED array , something alike a curtain .
If there are any existence of local dimming , there would be at least improvement on the numbers of black levels or brightness .

The last model I have inspected indicate this TV peaks at 300 ~ 400 nits , which is a common standard for modern UHD TV.
This is one of the most pretentious and wrong thing I have heard in this forum for a while .

Local Dimming is the system that is responsible for brightness output of the screen . They are closed related . How is that a different story ?
And of course we are going to talk about HDR , why do you even need a local dimming system for non HDR stuff ? Did you even hear yourself ?

You clearly have not even seen a FALD TV ,  nor you have any idea what is a local dimming system if you think its only function is to dim down the backlights .
You are only reading it by the name , which is limited by your understanding of TV's backlight system.
Again , for the 10th millions time , there is a HUGE difference between the hardware based (which is also called Local Dimming ) and software based dimming system .
The only one twisting the facts here is you because you are too ignorant and stubborn to learn .

Also , I am not responsible to give you a lecture since you are too lazy to even google .
People have already reviewed this TV and all the numbers are out there , the result is clear . It isn't even up for debate .

Even if we are to assume this TV has local dimming , it does nothing to improve on the picture quality . If that is the case , what's the point ?  Why are you being obsessed with benefits that don't even exist ?

Also the model Vincent reviewed is different than yours . If you watch his videos then you should remember the keyword " pseudo local dimming " . That is like a more polite way to say the dimming system is completely sh*t.
Last but not least , I assume you are capable of understand what does the word " BARELY " means , right ?
To summarize , I do think there is some sort of dimming system within the GX800 models but they are definitely not the hardware based LED Array zones we are used to be seeing on the market.
It is more identical to the same thing many brands are calling Global Dimming / Micro dimming / Frame Dimming  , a software based dimming algorithm on their entry level TV .

bro already I compare gx740 and gx800 the differents I found two

a) Super Bright Panel vs Super Bright Panel Plus ( any different?)

b) Dimension for gx740 - 1235 X 716 X 45 mm

    Dimension for gx800 - 1231 X 714 X 44 mm
it seem gx740 is more long than gx800  and the price different between two is only about RM 500.00
If I plan to watch 4K movie is it better I choose 55 or 65?

C) if the distance around 1 - 2 meter, which is better 55 or 65?

How long you have used it?
You need to compare the purchase of new tv vs repair with warranty?

If you were to buy the extended warranty upto 5 years.. you are covered for panel fault.