I would have to add in that this is probably one of the most perfect camera systems ever made, the lenses are sublime. The only issue someone might have with it are the lack of metering in the camera body (a matrix meter that covered the full frame would be prohibitively expensive I assume) and the fairly large size and weight of the system components.
I've got 2 of them a GX680III and a GX680II, both equally good, I've also got three lenses, 125mm f/3.2, 190mm f/8 Soft Focus, and a 180 f/3.2 (which is an AMAZING lense)