<p>I purchased the Df-Kit on 11/28/2013, and basically left my D800 in my office ever since, because I greatly prefer the Df.</p>
<p>I have had no reliability issues with the Df at all.</p>
<p>There have been no operational bugs, every feature of the camera has functioned properly 100% of the time.</p>
<p>Never had to clean the sensor, which is a bit surprising, as I did have to have the D800 cleaned after testing some older AF-D 'air-pump' zooms, which I tested on both cameras. Although the D800 was purchase in 2012.</p>
<p>No cold testing or experience (live in Fort Worth), but the Df does run fine in 100+ degree weather.</p>
<p>Low light performance is where the camera really shines. I use the center AF point 80% of the time, and then occasionally use the outer AF points. I find the focus to be quick and accurate, even in dim interiors. Mostly I use older AF-D lenses on the Df, but it also runs the modern G lenses well. I do not shoot action (AF tracking) type stuff in low light, so no comments on that kind of AF performance).</p>
<p>My very favorite way to run the Df is in Manual mode with aperture ring lenses and the shutter speed dial for control. I like the AF-start button to focus, use the shutter button for exposure only. I use Matrix metering and the viewfinder exposure graph to set exposure, but do have the Fn button set to activate spot metering when I need to override the Matrix meter. The Auto White Balance isn't bad, but I do use the white balance Preset function in mixed light. I like to shoot Raw+Jpeg, and try to make the in-camera Jpegs come out right. My only gripe is, I wish the ISO button lock could be disabled, so the adjustment of ISO was equally as convenient as the aperture and shutter adjustments. But one issue with shooting like this is when I have to shoot the D800, I find its user interface to be overly cumbersome.</p>
<p>Hope this helps.</p>
<p>- Dan</p>
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