Have been shooting for over 35 years.
I have been shooting a D800 for the past few months. Also shoot a Leica M9, Hasselblad 903, and a Hasselblad 203. There is absolutely no difference handholding any camera as long as you use good hand holding technique, and follow shutter speed recommendations for the lens focal length you are shooting.
I am baffled where these myths come from. :)
Gosh, for 35 years... well, I agree 100%. I cannot understand how these things start, except, sometimes our minds will trick us. It does seem to fall into a possible scenario, that the old film grain, and digital noise, would mask some "shake" from the operator. And, as we are able to resolve more precisely the image, this would make the camera shake easier to detect. However, while this may be true from a theoretical point, in practice, it does not seem to hold up, yet. I say, yet, because if laboratory tests were conducted, the better the resolution, the more apparent the camera shake becomes. Think, an out of focus image makes it very difficult to detect camera shake.
Now I have hand held, Nikon F's, Canon 7, Zenza Bronica, Hassleblad 500c's, even hand held a Nikon F with a 900mm lens on it. Back in the 1960's.
But, the primary point you make is so absolutely true. It is the technique of pushing the release button, how we hold, or cuddle the camera, our breathing in some settings, all which contribute to whether we have the proper shutter speed for the shooting conditions. And it makes very little difference if you are shooting a D40 or D800, if one punches the release like an elevator button....nuf said.
Thanks for the input...great topic TTJ