Just to add my 2 cents worth, and before I begin let me state for the record that my order of preference would be LX3, G9 and P6000 in that order, and that I find that the LX3 performance is better than that of the G9 or P6000.
Regarding the sensor size, I got bad news for you. Yes the LX3 sensor is larger than the G9 and P6000, but not by much. In fact the sensor is only slightly bigger, maybe 10% at the most, which is tiny compared to DSLRs which are several times, even dozens of times, larger than compact camera sensor sizes.
So whats the bad news? Well the LX3 uses only 88% of the actual sensor for taking photographs. Which means if you do the math you'll find that the actual sensor used for taking photos on the LX3 and the G9 are the same.
So why the difference in photo quality? Well IMHO its due to the Leica lens and the larger aperture. If not for that then the photo quality would be the same...................
you may want to look at this
if you intent to shoot jpeg, ixus 960IS seems to be a better solution
if you shoot raw, Lx3 is fine.
G9 is neither here nor there interms of feature/convinence...
do note the lens LX3 is much wider, it may not be as sharp as the one starts from 35mm is IXUS or G9