So I got my RMA device for the rattling/clicky vibration motor in my 1st N6, and the good news is the new one is much, much better. No rattle, but a high pitched subtle "click" every so often. I can live with that. But what I noticed is that the new device's brightness is a little lower at the same brightness level from my first device. Also, the replacement seems to have a cooler overall screen than the first one, and some pinkish tint on part of the screen. Not very noticeable really, and I can live with it. I did notice that the black contrast is "worse" on the replacement looking at display tester, but that actually translates to better video playback in dark videos for me as the compression (macro blocking I think it's called) was very visible on the old device, but hardly there at all on this one. Anyway, the brightness definitely seems to vary quite a bit and could explain why some are complaining of the screen being not as bright while others are fine with it. In my case, they aren't too far off. I had to put the new one at 30% instead of 25% to get the same (perceivable) brightness side by side.