I think I should make this additional comment.
I am at my office now. No windows close to my cube, but good light above me. Took my Kindle out (while I wait for a billion records to be inserted on a database
) and the minor uneven light distribution at the bottom IS GONE! You can't see it at all!
I asked a coworker and he saw nothing wrong or lighting problem, so it's not a "placebo" effect from my side.
Based on that, rooms with very low light or in absence of total light (at bed), you can barely see the spot light at the bottom. This maybe explains why during press conference it looks so good. Lighting is almost perfect on those events.
Again, not justifying Amazon, but I thought it was nice to clarify.