Both of those look good. How about the Panasonic Z95B?
From what little I've read it's almost perfect, Panasonic used to actually pre-calibrate their high end TV's years ago but I don't think that's the case anymore (in fairness it may not be as necessary with modern OLED's, and it's not exactly a good marketing niche for the layman).
They are quite chonky/thick due to the built in audio system, some people prefer a slimmer screen that's more flush to the wall or would rather have an external soundbar or AVR setup.
From what I gather it boils down to the following with high end OLED's with the main three:
LG: No nonsense, excellent screen with as far as I can tell the best overall connectivity features.
Phillips: Ambilight - aka reactive backlighting, personally I absolutely love it. Also has a built in 3.1 audio system vs the 2.2 of the C5, and of course the aforementioned 100 day trial/money back.
Panasonic: Chonky but amazing TV, comes with built in 5.1.2 which easily makes it the best choice if you want good sound without a soundbar or AVR.
They've all got their niches tbh, people tend to blanket recommend the C5 and don't get me wrong it's a fantastic choice, but there's absolutely good reasons to go for other OLED's at the price point.