Share your experience!
Hello,
I recently purchased Xperia tablet Z, and I have been observing difference in brightness of screen as top of the screen(near SONY logo) is brighter than bottom portion.(I am still on 4.1.2, dont want to upgrade as placement of soft buttons has been shifted in middle than left corner)
I called Xperia care and they asked download Xperia™ Diagnostics and run Display test.
When the Screen is white for 10 seconds this difference becomes more visible and prominent.
Can anybody confirm is it observable in all units or its just my unit that is faulty.
I may have a related issue; the "top" quarter-inch or so my screen is barely dimmer than the rest of the display. Like your device, this is only noticeable on white or evenly colored screens when holding the table in portrait orientation. My first Xperia Tablet Z had this issue, I exchanged it, and the second one had the same exact issue. I'm otherwise happy with the device and since this is only really noticable under specific conditions I've decided to accept it ...
How did you get it exchanged?
I doubt Sony Service Centre in India will replace the product, rather they will keep it for ages and make me wait by telling that particular part is being imported from blah blah country so have to leave my tablet at service centre 😞
But i'll give it a try.
Such faults are not acceptable at this premium price.
I bought it through newegg.com in the U.S. and exchanged via their standard returns policy. Pretty straightforward. I was tempted to just get my cash back, but I needed the tablet for some stuff I'm working on and it seems like every tablet has some glaring flaw -- if it's no the screen, it's the lack of an SD slot or something else ...
Bump..
Has no forum member noticed this issue??
I have checked at few sony stores and observed all tablets are more or less plauged by this issue. 
Will updating to 4.3 make any difference?