After thinking I had a keeper, I'm returning to the Apple Store for yet another replacement.
My Samsung screen has a yellow to blue/grayish gradient from left to right.
It isn't noticeable on it's own but on this forum the left side of the screen is clearly tinted differently from the right side.
Beginning to find this a bit absurd.
-My rMBP from Amazon was horrifically squeaky and had an LG with a pink corner.
-First one from Apple was noisy (CPU or iGPU were obnoxiously loud; I can attest to this as I've now had experience with 3 different machines).
-Now this current one has uneven tinting.
Will be moving onto my fourth machine this week (third directly from Apple)
Not sure if Retina is worth all this trouble (coming from a perfect, albeit cosmetically worn, 2009 17" MBP)
I will decide on the drive over to the Apple Store whether to try my luck on a fourth machine or to just downgrade to a maxed out MacBook Air and not have to deal with Retina screen issues...