Got my lighted cover today and so far as I can tell with the K3 in it weighs about the same or slightly less than a the K2 with the old Amazon cover. It is just as comfortable to hold for long periods. (I read about 200 - 250 pages). In low light the uneven lighting was mildly annoying but not aggravating. I would not want to read with it for hours but for dining out (nothing better than good food, good wine, and a good book) it would be perfectly acceptable. For power outages it would be lovely since it is right there, no searching for that clip on or a flashlight.
Harry's point about slight differences in deployment angle strike me as reasonable, with time I can see that the plastic arm may change. I spent some time flexing the arm and it is clear that the default angle that mine has is sub-optimal and just a slight deflection evened out the lighting across the reading area.
I am very happy with it.
(And, as Harry pointed out, if you fall asleep it goes out by itself. That's something no other light is going to do.)