The problem with higher and higher picel counts, especially on a u4/3 (sotty, Micro four thirds), is that it increases noise. We already use 30 second exposures, and using smaller photosites in conjunction with this makes a picture at a Given ISO more noisy.
Otherwise, it looks nice. I was looking very heavily at the predecessor to this until I got a great deal on something else.
Very true, i've got the older G1, and the noise on a 30-second exposure is pretty bad, at one minute the noise is awful (been experimenting with strong infra-red filters).
However the flip-out screen on the G1 is incredibly useful and the manual focus excellent.
Recently bought an LX5 - more convenient to carry around underground but seems to have problems focussing in low light...