This style of camera interests me a lot for something to carry around all the time. However, as a 2nd camera I don't think it needed to have 20MP, I would have much preferred a 12MP sensor with better high ISO performance.
I was particularly interested in a comparison with the G3 but as others have said, it is impossible with the differences in exposure. For a useful real-world comparison of noise at high ISO you would have to set the shutter speed & aperture and adjust the ISO until the exposures were equal and then look at the noise.
I think the only conclusion that I can draw from this is that the OM-D doesn't blow the G3 out of the water. Given that, I would say the G3 is a real bargain.