The Panasonic 20mm f/1.7 is a much better designed lens than the 14-45mm kit lens... probably why Leica dare to put their name to it. Images from this lens look good even on my E-P1 and E-P2.What about the panny 20mm f1.7 lens? Do Panansonic did the same? :dunno:
But Panasonic has also used software correction to make the images from this lens look better. This is described in detail in dpreview's review of this lens where they compare the use of this lens on the G1 and the E-P1...
http://www.dpreview.com/lensreviews/panasonic_20_1p7_o20/page3.asp
So the morale of the story here is that Panasonic lenses perform the best on Panasonic camera bodies as long as the users do not delude themselves into thinking that the true optical quality of their Panasonic lenses are really that good