With respect to Christine, it is, of course, horses for courses.
For me the Pentax Q has zero interest... I've found m43 as small as I need (I always carry a small bag so I don't need a literally 'pocketable' camera, and the GH2 pushes the boundaries of ergonomics...) and my number one grumple with Four Thirds in general is limited DoF control, so any change would be toward a larger sensor, rather than a smaller one (unfortunately the only compact FF body is the M9, and I don't have a handy $8000 + lenses).
As it happens, I've just ordered an X100 as a 'carry everywhere' camera. For me the combination of sensor/body/lens is absolutely perfect, it is literally exactly what I want.
Naturally though, what
I want is not at all what
everyone wants, and from what you've said the Q sounds very suitable (although I'm still dubious about Pentax's IQ claims - shall wait for reviews I think
)