I thought it was interesting that I thought my 2015 13" rMBP had a shockingly warm and unevenly tinted screen when I first got it, even after calibration (I need accurate screens for my work).
I googled the issue and found many posts on this forum about it without prior knowledge of the issue. I think that is pretty good proof that people aren't imagining this along with the fact that the screen is very obviously not a good screen. It takes only a few comparison photos and measurements between this and my 15" rMBP to show that the LG screen on this thing is greatly inferior. I think the problem has been more common with the LG panels, but I haven't seen any hard statistics, so the Samsung ones might have issues too.
The only reason I didn't bring mine in for replacement is because a) I don't think I'd get a good replacement panel, and b) I don't have the time as of late to do a ton of replacements, unfortunately (would if I could!).
In addition, I work on other machines most of the time, and they have good screens— a 15" 2014 rMBP a lot of the time, along with nice Dell monitors at work. So it isn't a HUGE issue for me to live with this. But for people who depend on color accuracy and for whom the 2015 rMBP is their primary laptop, it is a really big issue that should not be trivialized.
The color problems with this screen are not minor like having a few dead pixels. I'm talking an entire screen being FAR too warm after calibration, and half the screen being very noticeably off-tint from the other. In fact, a corner of my screen is even noticeably DARKER than the rest.
