Got an LC-70LE757U a while back and recently had it calibrated - results attached at bottom.
My daughter has a BestBuy Reward Zone Silver status which includes a free Geek Squad visit, so she scheduled a Geek Squad calibration for me as a Fathers' Day gift.
The Geek Squad calibration was pretty brief and basic but it did improve the picture enough that my daughter noticed immediately "Wow! That looks great!" whereas she's usually oblivious to picture quality.
In particular, the set now has a more-pure white with greater detail in both the dark and bright regions.
I use the TV almost exclusively as both a Windows 7 desktop and Media Center TV at 1080p over HDMI or DVI->HDMI. My video card is an ATI Radeon HD 5870.
I had the calibration done on the Movie setting but find I get motion artifacts (even with all special options turned off) when using the TV with Media Center, especially when I use the 1-1/3 playback-speed setting in Media Center (which compensates the audio to sound natural, just faster). This sped-up playback is great for watching time-shifted news and sports, etc.. In 3 hours I can watch 4 hours of actual tennis or football (skipping over the commercials too, of course).
So I end up using Game-Standard mode most of the time to avoid the motion artifacts.
I copied the calibration setting over from Movie to Game and they look good, but not exactly the same.
I tend to get eyestrain if the picture is too bright, so have the backlight and contrast turned down as much as possible while still getting what I consider a good picture. The room has muted, indirect lighting but isn't particularly dark.
For what they're worth, the PDF calibration results from Geek Squad are attached (see bottom). I think they would probably vary with each individual set.
In all cases the Color Temp is set to Low and Gamma at 0.
Quad Pixel Plus 2 is Off
Active Contrast Off
Digital Noise Reduction Off
Backlight -16 to get the best blacks.
The 10-Point Setting is Off and the 2-Point settings from the calibration are:
R Lo +10
G Lo -2
B Lo -19
R Hi -5
G Hi +4
B Hi -9
I find the basic settings to be different depending on whether I use the DVI or HDMI output of the video card. Overall, Media Center seems to work better on DVI but I sometimes use HDMI when I want to use the TV speakers instead of using my amplifier.
I've tweaked the basic settings since the calibration and am currently using:
Game (Standard) on HDMI output:
Game (Standard) on DVI to HDMI cable:
Movie on HDMI:
Movie on DVI to HDMI cable:
The full report from the Geek Squad calibration is attached.
GeekSqadCalibration.pdf 569k .pdf file