Several posts above say that the Voyage is brighter than the Oasis, which does not match my memory. (I am also not sure what that even means. Since they each have 25 settings, I suppose that the setting should be the same on each.) The Oasis light is completely off at 0 and the Voyage is not, so technically the Voyage is brighter at 0.
Last year, I posted side by side pictures at 11 levels from 0 through 24 at
https://www.mobileread.com/forums/sh...d.php?t=292336
For levels 1 through 9, the Oasis is significantly brighter than the Voyage and level 1 on the Oasis may be too bright in total darkness for some people (I use 3 or 4 myself on the Oasis and 6 or 7 on the Voyage in total darkness, some people have complained that level 1 on the Oasis is too bright for them in total darkness).
Levels 12, 15, 18, and 21 are slightly brighter on the Voyage, but 24 is brighter on the Oasis. So the Oasis can be set brighter and darker than the Voyage and therefore has a greater brightness range. But the Voyage has finer adjustment at the darkest settings.