Speaking as someone who has run quite a few hundred foot loads of ECO through an Arri-S myself, I have to say Chris that I'm pleased and not surprised.
I'm not surprised that the Canon was difficult to use as a motion media recorder. The form factor seems anything but Operator friendly. For those not of the film world, I add that "Operator" is a very specific term, one referring to the business of operating the camera during the shot. For stills people this term is more or less meaningless, since the "during" part is usually very small fractions of a second. For Camera Operators, the "during" can be minutes long.
For Camera Operators, the viewfinder is everything. You need to track, compose and focus in real time for a long time. DSLRs just can't cut it. The small, fixed viewfinders (both optical and electronic) of any DSLR pale next to the bright, clear, articulated, prehensile viewfinders on modern film and video cameras. Holding the camera at arms length to view and compose is easy for digicams and single shots. For heavy DSLRs, it's not gonna fly. Even with IS, your arms just aren't steady enough for long enough.
I'm pleased, though, with your comment that the system is intolerant of operator error. With that intolerance goes precision and capability. When the hardware outstrips the operator's skills, that's a good thing. The quality and flexibility of the interchangeable lenses and the resulting imagery is evident even on the low-res Quicktime videos you posted. That bodes well for us all in the near future.
For now, it looks like the Canon would be a superb tripod-mounted camera for landscape video, especially time-lapse.
Was the sound we heard on the Quicktimes recorded with the camera mic?