After one week in with my KPW I can say that I think it will be a quite happy relationship, between the little gadget and myself. I can't comment on how it compares to other e-readers, given that this is my first (and that rooted Nook ^^ has me a bit jealous atm), but it certainly delivers what I was hazily expecting.
The uneven lighting at the bottom pretty much vanishes from my perception as soon as I get immersed in whatever I'm reading, so that's alright -- though I must call BS on Amazon's official stance that the lighting imperfection is limited to areas devoid of text: A couple of lines at the bottom of the page definitely overlap the blotchy light when it's turned up to, or near to, max. brightness.
Besides that, I thought the small size a weakness when I first unpacked the thing and was thus mildly disappointed, but it really is nice and light and lends itself to one-handed manipulation better than a larger device could have. So its small size is actually starting to feel like an advantage, and one screen-full of text is enough that I don't feel like I'm constantly having to tap for the next page. Though a slimmer bezel coupled with a larger screen would of course be an improvement; I guess that'll have to wait for the future. And I could see how someone using a larger font would be forced to "turn" pages awfully frequently.
Speaking of the future, it really would be something, it seems to me, if they made this thing waterproof. How hard could it be? I mean it already pretty much forces me to rely on WI-FI, and it only has the one physical button, and they already cut out those features which would commonly imply imput/outputs (sound, I guess). Except for charging through the USB and the initial setup (both of which can to an extent be made to be wireless, or just waterproof gold contacts for power), there's apparently no need to ever jack into the device.
And as much as I love paper books, that's one thing I've always begrudged them: their inability to weather an unexpected storm.