I've had 3 rMBPs now (2 LG, 1 Samsung) and my last one, a Samsung, had a strange issue where there were a few dark "splotches" about 2-3 inches long in the middle of screen. The LG that came before it also had the same issue but they were so light that it was generally unnoticeable. It's an odd issue since on a static image you can barely make it out but if you move a window around they become quite apparent. In fact, it kind of looks like the screen is dirty in some section (it's not); it's either the backlight (likely) or pixels (unlikely). It's one of those "once seen, cannot be unseen" type of problems. Anyone seen this? Either way, going for a forth unit and then...well...I'm probably done.