I'm really frustrated with the Lumia 930. I replaced the first one because the screen was darker on the bottom. (The seller didn't want to replace, he said he didn't see it, even though everyone I showed the phone noticed it).
The first one had the purple tint, but I managed to fix it with the display app.
Now, the second one has the purple tint and even setting the tone to green it still has a purple tint, it's not as purple as the default setting, but it's still purple in low and medium brightness.
Another problem I have with the second unit is with the touch on the top of the screen, I often have to to swipe two, three or four times to open the notification panel. It's specially bad in the top right corner of the screen.
I've read every post here and only one other person complained about this problem.
And the speaker is crappier than the 820's, the sound quality is worse, it seems that the back vibrates with the speaker and the sound gets saturated, I don't know exactly how to explain, but everytime I get a notification, a little part of me dies inside. hahaahhah
Now, I can't replace it again, here in Brazil it's very complicated to get a replacement, sellers don't trust you or claim that your device is perfect. Specially if you didn't buy the phone at an official Nokia store, which was my case.
It's an expensive device, it shouldn't have these issues. And a lot of the issues it has, older devices don't have.
My Lumia 820 works beautifully, the colors are perfect, the screen light is consistent, the touch is perfect, the sound is perfect.
The build date of my device is August 8th, and it has the same problems of the earlier devices.
I don't get how Nokia can release a device that is basically the Icon and has the same problems that were already fixed on the Icon.