I'm very OCD when it comes to my e-reader screens, so I just want one with lighting I can live with or it will bother me forever.
I had a Paperwhite 4 that was completely even. Too bad I hated the swiping after I was used to the Voyage. But I don't think it's too much to ask the lighting of an e-reader to be even. I mean, you stare at the screen for hours every day (or at least I do), I would like it if manufacturers could get that one thing right. E-readers have been around for a while but the screens are still a gamble.