There's one thing that should be made clear however. "Tests" like this are subject to all kinds of variables. How I hold each camera and the design of the camera are important. I obviously tried to keep it as similar as I could and made sure that I braced myself, breathed in etc. in order to make all the shots as stable as I could. However that is no guarentee of consistency.
The problem with any test of Image stabilisation and that I guess is why you don't see too many, is the fact that its almost impossible to devise an "objective" way of doing it. Certainly I can't think of one since it involves hand-holding different cameras.
I think its impossible to say which is the "best" system as I think this depends on the individual photographer and how they work. Some of us may find it easier to work with lens based systems, some with body systems. The latter obviously gives more choices, since not many lenses have any form of IS built in.
Finally, its not something I do a lot of. I very rarely use these kinds of shutter speeds hand-held, so I'm no expert. I have a reasonably steady set of hands, and the majority of my images are hand-held, but I tend to use much faster shutter speeds for this.