porktaco, I have noticed a similar phenomenon. I tend to think that the answer depends partly on the sort of motion that is being blurred, and also on what you are used to. For example, in my film days I would usually get noticeably less blur of objects moving across the frame, when employing a horizontally-running focal plane shutter, than when using a between-the-lens shutter. The reason lies partly in the fact that the focal plane shutter exposed only part of the moving object at any one time, and either tended to pan with it, thereby reducing blur in a rather obvious manner; or, if the shutter and the object were moving in opposite directions, the camera recorded the moving object for a relatively short amount of time, again reducing the noticeable effects of blur. In comparison, a between-the-lens shutter effectively exposed the entire frame at once, creating a relatively large amount of opportunity for blur.
Of course, analogous arguments apply to objects moving vertically in the case of a vertically moving focal plane shutter. If objects are moving along a diagonal trajectory then the arguments apply to a lesser extent, but the outcome (in my experience) is often still visible. I feel that the arguments should also apply to camera shake.
The older focal plane shutters were relatively slow-moving; the experience described above was gained on focal-plane shutters on 6x6 and 6x7 SLRs from the 1950s, 1960s and 1970s. The shutter on a NEX7 moves much faster (as dictated by the needs of live view), and, of course, uses an electronic front curtain; all of which conspire to expose the whole frame for almost all the time of the exposure, particularly if you are using a relatively slow shutter speed. This provides a greater opportunity for blurring. (In my medium-format days the arguments above were appropriate down to about 1/25th of a second, at which point the focal plane shutter started to use the front and rear curtains separately, rather than together to form a moving slit.)
I also agree with Dylan--we are probably pixel peeping too much! Nettar
