The point remains that these tests are not conclusive. These forums are a resource for a ton of people, and someone browsing the web for information could stumble across this thread and be misinformed. The article about mirror lock-up doesn't add any more validity to the argument, because it's not even in the same vicinity as Quiet Mode.
Joe is still correct:
But to say that the images first posted in this thread were the direct result of being in Q mode, vs. not being in Q mode is crazy.
To perform any kind of accurate measurement, there must first be a standard established that is the same across the board. If the test is to measure image sharpness in Q Mode vs. normal shooting modes, all other camera settings must be the same. The environment must be the same, so must the lighting, and the subject. All efforts must be taken to remove any outside other influences...in this case, camera shake. Definitely on a tripod, and ideally using a remote shutter trigger.
That said, I will argue that using Q Mode is actually going to produce
less sharp images on a tripod, because you have to have a finger on the shutter button to use it. Handheld will not produce consistent results, no matter what the variable. It may be more sharp in the mid-slow speed range, but that's about it.