Own a Kobo Glo for about 10 days. Removed the sticker on the first day. Did not notice any issues on the screen first days, while my kid used the device. After that uploaded some books for myself and started using it extensively. Few days ago found a bright pixel in the middle top part of the screen. A couple days later found another one on the same vertical line closer to the bottom part (above the bar). Less visible as it's position right atop the letters in the line. The first one is more annoying.
Moreover, maybe it's just me, yesterday in the evening after thorough exploration of the screen with light on in the left bottom part I noticed some sort of fogginess. No effect on the text, just uneven background. Maybe just because I used it with light on for a long period. I don't see it right now, after just switched it on again in the morning. This one is not a showstopper, still an interesting observation.