So while debating whether or not to try to exchange the machine for a new screen I discovered that my right USB port is non-functional. To be more specific, it requires a bit up and down wiggling to get a USB connection with any device, while the left port works perfectly.
I tested a number of devices which all show the same results. When wiggling a plug to get the connection a message pops up in OS X saying that one of my USB devices is using too much power (again this is with anything; mouse, keyboard, xbox controller, iPhone, external drive, thumb drive). That would point to a short or just a partial connection internally.
Anyway, while this is apparently not a common issue (only found a few cases of this from Google), the whole thing has left me really uncertain about Apple's QC this year. After more careful inspection (helps to put it against a background of equal brightness by the way) I determined that my screen did indeed have "warm" and "cool" blotches regardless of angle. The failed USB port is the final nail, so for now I'll be returning the machine entirely. I'll likely live with my 17" for another year and reassess at that time.
Very unfortunate, because aside from these QC issues I think this is the best laptop I've ever used. I just don't trust that I can get a screen that matches the advertised quality at this time.
I would not hope for any fix regarding the yellow tint on Samsung's displays. I have always found Samsung's screens to be yellowish. That's why I don't buy their TV for instance. Even the androïd phone from by brother has a yellow screen. It's just the way they manufacture their screens ... I don't know the reason, I'm not an expert in the area. Clearly they are of inferior quality to the LG screens (I have seen more reports of dead pixels, uneven colors or light bleeding problems with the samsungs screens) but they are immune to IR which is the most important in my opinion. Indeed at some point your are not going to be able to use your computer because of IR when a yellowish screen is still usuable. Of course it´s still not the perfect screen Apple is selling you in their adverts. but I think I would stick with yellow of fear to get an LG screen.
Apple needs to ditch both of these losers and see what Sharp can produce for them, which is hopefully the plan. Sharp has a reputation in the TV world for making very good panels, including the only LCD ever to enter competition with high end plasma (the Sharp Elite full array LED local dimming panel).
I would pay a premium for a higher uniformity panel. In fact that's kind of what I already thought I was doing with the rMBP, but apparently not.