I'm personally a big fan of the Kindle lighted cover but you may not want a cover as well.
Anyway. I can tell you that personally, I love it! The light is bright enough to light up the whole screen without being too bright and disturbing the hubby while he sleeps. Yes the light is brighter towards the top of the screen and slightly darker at the bottom of the screen - I think this would be true with most clip-on lighting. But, if that's something which would bother you then maybe the lighted cover's not for you.
It's very clever the way in which the light retracts into the cover when it isn't being used. I did used to get sick of putting my clip-on light on and off my old Kindle 2 and then either hunting for it when I needed to use it or wondering where to put it when finished. With this cover, you know the light is there ready to use at any given moment - and you don't need to hunt for batteries!
Another smart thing is that the light automatically turns off when the Kindle goes into sleep mode - thus preserving the battery of your Kindle. This was great last night when I nodded off while reading.