The TV I bought had issues...
I took this pic with my iPhone unfortunately, with a gray image displayed and you'll need to ignore the window and light glares, but at least you get the idea of the vertical lines it displayed.

The lines were visible behind a variety of colors and lighting. I went though every picture option and moved all of them back and forth to see if that would fix the issue. It did not. It was like I was seeing the LEDs though the LCD panel or something.
Outside of this issue, after I figured how to turn the 120Hz crap off to remove the soap opera effect, the picture I was able to display from Toy Story on Bluray was impressive. So I knew if I just got a 'good' TV I'd be set.
Last night we packed up the TV and exchanged it for another (same model)
Once that TV was setup, I was happy to see the vertical lines were not there. But since luck is rarely on my side, I went from one issue to another...
(Pic taken w/ DSLR on Tripod, 5 sec exposure, no lights on in room, 100 ISO) Default Out-of-the-box TV settings. The mute icon is there because in default mode if you view a picture that's 100% black, the TV will go into a deep black mode (not sure exactly what it does but it looks like the LEDs go off or something) so mute was the smallest thing I could make the TV put on screen to force the LEDs to be on.

Based on the few hours I spent looking at different material last night including Blurays, DVDs, HD & SD + test pattern images from Apple TV, the light leaking is too much for me. So unfortunately I'm not happy with this TV either. The light leaking is distracting and visible in all dark scenes and all over Apple TVs menu system (which is mainly black) and frankly, after spending $1500 I expect my TV to look good and I know this model can provide me with the picture I want if the TV was without backlight issues.
The UN55EH6000 is a direct lit LED, would I have less issues with one of the more expensive (but thinner) edge lit LEDs?
Do you have similar issues?
That brings me to Best Buy questions...
Has anyone here exchanged a TV a SECOND time? a third time?
Will I be able to swap my TV again?
What happens if the next one is just as bad or worse?
At what point will Best Buy start getting pissed off?
Please share your experiences.
Thanks!