Well I guess it will always come down to opinion.
In some of the demo scenes I saw, the LG was superb - there was a costume musical / drama scene and the faces and clothes and everything really had very nice natural beige tones. On other sources though, greens looked fluorescent especially on grass eg because of this, I got the store to switch sources to a pre-recorded BT Sport 4K football match and again the pitch was fluorescent looking. The tv was also superb with motion (which kind of flies in the face of the WhatHiFi review as I didn't see any of the jerkiness they talked about, albeit maybe football is too slow to cause issue). However, the crowd was another matter and when a goal was scored, the jumping around of so many people did cause so slight issues although whether that was BT's encoding or LG's tv is impossible to say. Motion was ver good though.
Don't get me wrong, the LG is superb but for me, at least on the settings I've seen in both shops now, it has 3 main issues:
1. Oversaturated colours, especially greens in HDR which can result in them looking un-natural
2. On blacks and dull scenes especially, the screen is very matt (not sure if this is the result of an anti-reflective coating or just a characteristic of OLED). However, to me it looked un-natural in some scenes compared to the shine I was seeing on others.
3. The lack of greys was very pronounced in the Moon Sweep demo as the moon went from almost white to black in avery defined line as the shadow swept across, which again looked un-natural as you would expect a grey margin as a transition between light and dark.
By contrast the 902b, had very few faults I could discern. I couldn't see anybacklighting issue or the overblown highlights I'd read about, instead the picture looked superb. My only critisism would be that upscaling was very poor with SD which meant that you need to really pay attention to the panel size because if you sit too close it's going to be very apparent - by poor I mean pixellated and heavily artefaced - I was watching BBC news in SD.
As for the Sony, saw it in JL, and it looked very nice in there. Curry's didn't have it which was a shame as thier viewing area was much darker and much more like a home viewing area.
Overall though, I feel so far, there's very little to choose between them with 4K / HD. The Sony to me is the more middle of the road set. Very impressive but it lacks the dynamics of the other two sets. The LG is overblown at times but very impressive on blacks and motion. The Panasonic in 4K HDR was the most impressive to me on non black pictures, somehting which LG seemed to avoid in their demo mostly - maybe because they can't compete on brightness? The impressive pictures on the 902B from memory were the surfing, the lake looking into the sunlight and the fruit in HDR. In the fruit scene, I felt the colours were up there with LG's OLED. In the city night scene, black levels weren't OLED standard but nevertheless, very good.