Ah. The joys of the internet.
Whatever did we do before the world wide web?
Read a magazine. Go into a shop and formulate an opinion based on what we'd seen with our own eyes?
I remember doing this 7 years ago with all the hooha about Pioneers Kuro. We did a side by side demo of the Kuro against the RGB LED Sony flagship and there was only one winner.
OLED could be good when it's the finished article. But it's not. Yet.
Sad to think that a TV that cost £2700 7 years ago is now worth less secondhand than the backlit remote control it came with.
You picked an early LCD over a Kuro? You need glasses
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Up until OLED, the Kuro was the best TV I have owned.
Hey OP i hope i can help by shedding some of my experience!
I was in the same boat as you earlier this year but ended up with the LG OLED. I can see where you're coming from when it comes to the brightness/nits when it comes to OLED but for me it's more than enough personally.
The KS8000 was very bright in comparison so i understand where you are coming from in that perspective, although if i aren't mistaken it was 1000 nits at peak brightness and could only handle that brightness for a small period of time.
I'm very happy with my OLED over my old KS8000 that had multiple issues. The T.V got sent in for repair four times all with the same fault on return i had 2 new units after that with the same problems and on one a major issue.
I might of had just really bad luck when it came to Samsung but that's just my experience with them. As a matter of fact if i had no problems in the first place i wouldn't have my OLED right now.
But i'm over the moon with my OLED to be completely honest and if i had a choice to buy the T.V again and i had to pick between the Samsung or the OLED it would be the OLED 10/10.
Not because Samsung left a sour taste in my mouth but after sitting with the T.V for a few weeks i instantly preferred the deep blacks OLED offered compared to LED or Samsungs new QLED as my friend has one and he admits it's not as good as my OLED.
Also Dolby Vision is a + and the fact that WebOS is so fast and clean it's leaps and bounds above any other competitors in my opinion.
Regardless i think you'll be happy with any Television you decide to buy i hope you don't have the same bad luck as me when it comes to the T.V.
Good luck!
Edit: Maybe try to wait till Black Friday for deals on T.V's then if you can wait.
That sounds like an annoying experience. My KS8000 has been fine.
I actually found the KS8000 too bright at nighttime to the point it would hurt my eyes when there was a big flash of a bright colour.
@OP - please try to at least throw the brightness argument out the window, with the 2017 models - it's no longer something to concern yourself with as they are more than bright enough.
I have a large south-facing window in my living room, yesterday was sunny with blue skies - the sun was streaming in through the window and I still had a comfortable viewing experience that exceeded the KS8000. The anti-reflective coating on the OLED is better than the one on the Samsung, so I had less reflections in the screen where they could obscure viewing even on the "brighter" KS8000.
I can understand light/reflection issues with Plasma... both my Kuro and Panny GT30 were washed out in bright light.
If you're keen on using the in-built streaming apps... the Panasonic's interface is terrible - I bought one for my Grandmother, but she doesn't use that side of the TV. The Sony isn't much better.
The Samsung interface is a pleasure to use - almost as good as WebOS on the LG.
I was comparing the same options as you (well, 55") when I got my Samsung and went with the Samsung because I thought it had the nicest / warmest colour reproduction and vibrancy which noticeably exceeded both the Panasonic and Sony. I didn't realise til later the differences between the user interfaces which would have really annoyed me on the Panny especially - it feels 10 years old. If you won't be using that and only plan to use external sources, then it's not relevant.