I've got the 300 light cover and I actually like it. The photos someone showed or NOT accurate as photos tend to not show direct light very well. I don't have a spot on my screen, at least when I adjust it correctly. (If used a MightyBright light in the same fashion as the photo of the cover light, and the photo was poorly taken as that one was, it would show a spot too.) And it is very easy to adjust and very easy to fold up out of the way. I also have a MightyBright I bought for my Kindle2, it is different from the one shown in this thread, but similar. The problem is that the clip is really way to big for the 300 or the 600. I think the MightyBright is a lot brighter, but it uses 3 AAA batteries in parallel. The 300 light cover uses only one AAA battery. I was initially disappointed when I turned it on in daylight conditions. However, I have used it for several hours at night in a darkened room as well as outside at night and it does a more than adequate job, even on low light settng. But different strokes for differnent folks, as they say. What works well for me might not work for someone else. But as far as I'm concerned the MightBright is overkill and bulky, but the light cover is compact and very useful.

Someone was trying to compare it to that garbage Sony sold for the 505. There is no way to compare the two as the 505 used a sidelit transluscent plastic shield that made everything fuzzy. The 300 and 600 light covers are more like a larger cover with a built in LED overhead light similar to the MightyBrights. The light cover for the 300 is not too big, for me anyway, but I could see how the extra width on a 600 might bother some people.

BTW: The Best Buy in south Arlington, TX has both light covers (for the 300 and 600).