55 seems way too dim to me on my B6. In HDR it sets itself to 100 but usually I have it on about 78.
C6 (and presumably E6) are brighter than the B6. I know this because I had a B6 for 3 months which I recently swapped for the C6 - primarily due to the HDR stutter issue. And the C6 is noticeably brighter and I have the OLED light on 60 whereas I had it on 80 on my B6.
Note the C6 shares the same SoC (and firmware) as the E6. Other things I've noticed moving to the C6 is that games feel so much better and more responsive (likely due to the lower lag) and the near-blacks are much cleaner and less blocky when testing the same scenes - a night and day difference, especially when comparing the church scene in Daredevil episode 1, which my B6 made a mess of.
I'm quite intrigued by the LG B6D.
55 inch is around 2,3k Euros in Germany but the 65 inch is 4k... I mean. What.
Any chance this goes to 2,5 with black Friday sales?
And even more important: any bad experiences with the b6d?
The B6 is a great TV. SDR input lag is a little high but tolerable unless you're mega competitive. There is also a stutter issue with HDR/24p content, but LG is currently working on a fix. Personally, if you don't mind the curve, I'd go for the C6. It's the same price as the B6 but offers lower input lag, 3D, a cleaner image, better near-black performance and it's a little brighter too. It also shares the same SoC and firmware as the E6, so you know you're going to get the best firmware updates in line with their main OLED model.
Probably worth noting, before I swapped my B6 to the C6, I initially swapped it for an E6, but I was unlucky as it had a green stain across the top half of the screen which was obvious on a white screen. But I decided to go for the C6 instead of a straight swap for another E6, not just because it saved me a few hundred quid, but mainly because I hated the design of the E6 when it was actually in my living room. I felt the integrated soundbar was really ugly (like a radiator from the 70s) and I much prefered the floating design of the B6 and C6, especially with my bias backlighting.