I tried it the quick route to run AOSP on the Xperia V to check screen brightness, but AOSP refused to boot and hang in a bootloop after flashing.
I can confirm that with different stock Androids (13 and 14) screen brightness is excellent. In Sailfish OS the brightness of the Xperia 10 V is much worse than on Xperia 10 iii. It is definitely not hardware related, since as soon as Android is on the same device, the screen is bright and not dim as on Sailfish.
Would be a pity, if in the final Sailfish release the brightness would not improve.
For me, the screen brightness was one major reason to choose the Xperia 10 V, and hardware is capable.
In the coming days I will definitely not find the time to tackle AOSP and the bootloop further