I sort of agree with you. I shoot a Nikon D3 and D300 (FX and DX), a Leica M8 (the sensor's a bit larger than the Nikon DX) and two Panasonics, the GF1 and the GH1, which use the m4/3 sensor, and occasionally a couple of small P&S's. I find that the small sensors in point-and-shoots do not match 35mm film in overall quality, but that all of the other formats, including m4/3, do match film in overall quality (I do not say match the feel of film.) In other words, I think the break comes between the very small P&S cameras, and the larger formats. M4/3 is smaller than DX, but not by much. In ordinary sized prints, I do not see much difference between full frame and m4/3 shot in normal light. The differences are most visible when you are pushing the light -- when you start shooting as ISO 3200 or 6400. If, however, you are like many forum members, and only look at prints under exquisitely balanced light, using a loupe, while listening to Bartok, then you may see some differences at lower ISOs as well.
JC