Cool!
I agree about it being fragile. I remember I was a bit concerned about it after reading on amazon, that one user broke the switch very fast. One must be careful when using it.
I used some very cheap AA batteries and they discharged quite fast.
A few days ago I finally put 2 AA rechargeable batteries, 2500mAh each and the light looks brilliant, I used it for about 4 hours and have not noticed any deemness so far. I think it will be bright enough for about 8 hours before it starts to deem, but have to test it yet.
(and yes,
having a bright even light is the most important aspect for me
along with no more worries about spending money on batteries, 4 rechargeable AAs is more than enough for me.)
P.S. btw I have not tried to read from USB. It would be very awkward to have a laptop running all the time (noisy as well) and they say it would not be as bright as with AAs. Also I don't like the idea of a cable connected to the lamp, I like it to be completely free of cables so I can turn in my bed any way I want to without worrying about cables.