I assume the Q7F you mean here , is the Q7F from 2017 , not the 2018 's Q7FN .
The QLED from 2017 has a very disappointing performance .
Behind the fancy marketing words like QLED / Quantum Dot panel, the only improvement you see from these QLED TVs is the improved color volume .

This will be noticeable especially when playing HDR content . Both TV supports for Wide Color Gamut , but the QLED are able to show deeper , more saturated colors under different brightness levels .
The 2018's NU8000 is a very dramatic improvement over last year's model. Compare to the Q7F,  it is much brighter , slightly better input lag and motion handling , free SYNC for gamers .

When we talk about Picture Quality , it usually refer the Native Contrast of the TV. The higher native contrast the TV has , the more sense of depth you will get from the deeper  black , which translates into higher Picture Quality. Q7F 's contrast ratio is just about the same as NU8000 , so the difference of PQ is marginal , at best .
To sum it up , Q7F is not an improvement from NU8000 , despite being a little more colorful , it is slightly worse in almost every aspect , particularly the brightness ratings which is a key to displaying eye popping HDR effects. The NU8000 is the better pick , larger screen size too .
When you decide to buy a high end TV , you need to consider the content you are watching  - HDR or SDR.
The advanced specification such as wide color gamut and higher peak brightness only truly matter when you watch these content / play these games.
If you want a QLED TV , do consider the 2018's models . They are a much better TVs in general , with a dazzling peak brightness that illuminate the entire dark room with just 1 small dot from the screen.

This ?

Just to make sure , cause I know some TV merchant are still labeling Q7F as 2018 and trying to sell it as new at some ridiculous price . Look for an "N" after the F
The 2018 Q7F(N) is a fantastic HDR TV .

Look at its brightness ratings , this beautiful thing can spike up to 2000 cd/m2 of brightness , where no other LED TV can reach beside the Q9.

What this essentially means when you watch HDR shows , the sunset , the torch fires , the neon lights,  the dawn star are able to display eye searing brightness to the level of creating sense of realism most TV can never reach. The QLED almost 100% PCI-3 color coverage is just an icing on the cake here, making HDR effect pop even more from the screen.

It is also a very versatile TV , also bright enough to overcome some of the strong glare from a bright room with full glossy screen finish.
And that is all on top of the new free sync features for gamers ( NU8000 also has this , but not the 2017's Q7F ).
The only downside ( sort of ) is it uses a lousy dimming algorithm , unable to boost its contrast rating past the typical Samsung VA standard. It is still good in this area , just not as awesome as its bigger brothers ( Q8 & Q9)
Between Q7FN and NU8000 , the Q7FN is quite a noticeable improvement . Whether if its worth going for the 55 inches screen , depends if you watch enough HDR content to justify the sacrifice. NU8000 is a pretty good TV to begin with.

I think she/he is referring to the RM8500 55 ' Q7FN & RM8500 65 ' NU8000

Received my set today and it is indeed Q7FN.

go shop but the vendor itself is from Ipoh

Yup bro, been thinking to upgrade for my current lg cx... Watching demo at shop of s90c, really impressed with qd oled haha... S95b also not too behind s90c i think