I just received the LTE version over the past weekend. Just before that, I got a refurb deal on a Samsung Tab 8.4.
Comparing the two, the screen on the Samsung just blows away the Shield. While nothing is "wrong" with the shield screen, the fact that the buttons are soft and take up precious screen real estate, whereas the Samsung buttons are hard buttons on the bezel, makes the Shield screen seem small. The Samsung screen is higher resolution, and whites are brighter overall, the colors seem nicer. The Samsung screen is not a AMOLED, so I would think the Samsung and Shield screens would look more similar.
I'm working with the screen set to "full screen" and just swiping to get to the buttons, and that helps.
Oddly, last night, my Shield completely drained the battery, to the point it would not turn on this morning. When I left it, it was over 80% full. I have the official smart cover and it was closed. After I fueled it up this morning, enough to turn on, I looked at batter usage, and Screen was 47% and Cell Standby was 17%. Cell Standby? I haven't even used the LTE yet (i've been on WIFI except for a quick speedtest on LTE) so not sure what this is. I don't like the fact that it died overnight, though. I will have to keep an eye on it.