Yeah, just compared my PW1 & PW3 with windows blinds down to refresh my memory. Make that more like PW1 level 0 = PW3 level ~4,5 (and level 1 = level 5)
When taking a photo with my phone it doesn't even see where PW3 is next to PW1 when both are on lowest setting.
IMHO no one could read on PW3 with levels 0-3 (and those levels can only be used to find your PW3 in the dark), maybe even 4 ... with it being the only light source, while PW1 on levels 4 and 5 is already killing my eyes and is readable on levels 0 and 1. On PW3 there is significant increase of light starting with 5,6 and 7.
I think those changes on lowest levels were made with PW2 and are for the better IMO.
I'm 30 year old with perfect eyesight and most of the time read indoors after sunset on my PW3 using levels 8-11 + floor lamp (or around level 6 during daylight hours) , always preferring for ambient light to do most of the illumination as opposed to just upping the level of built-in light.
The only time I've read in total darkness was when there was no electricity and I've always went to my Nexus 4 with Lux app installed (and light temperature changed) after brief struggle with PW1 crappy clouds. Never even tried reading in the dark on my PW3, but short look at its screen in total dark shows much much more evenly lit screen and better contrast. But still I wouldn't read in the dark :P