I'd have to vote C9. I still prefer the picture on our B7 over our z9d..even with the extra brightness of the Z for HDR.
I just had to make the call between the Q900, Z9D and C8. I game 65% so I chose the Z but not a day goes by that I don't wish I'd felt confident enough to get the C8 (still have burn in fears).
For what it's worth, my wife games for hours almost every night on the B7 and after 1.5 years.. no burn in.
Ascend Sierra Towers w/RAAL, Ascend Horizon Center w/RAAL, Ascend Sierra 2 surrounds, PSB Imagine XA Atmos modules (x4), SVS PB13 Ultras (x2), SVS PB12+ (x2)
Denon X6500H / Emotiva Mini-X a-100
Panasonic DP-UB820 / PS4 Pro / XBOX 1X
Sony XBR75Z9D, LG OLED65B7A