Whats up with Panasonic 14mm and 20mm on Olympus

One's mileage may vary. My 14mm/2.5 lens is quite sharp at open apertures and has given me great images indoors as well as outside. Some copies have centering/sharpness problems, though. My 20mm has also been excellent - but low light is a challenge because of the focusing mechanism and because of the possibility of banding on Olympus bodies. (Maybe no banding with the Pen-F, though, and definitely no banding with an Olympus which is using a fully electronic shutter.)

I've never had a significant problem with focusing using either lens on an E-M10 or E-M5 II, though I do think it's worth considering that these lenses will focus faster, if not better, on Panasonic bodies.

I bought the 20mm lens because I believed the comments that banding only occurs at ISOs above 1600. Not true, unfortunately. I found the banding to occur at all ISOs and at all apertures except f/1.7. But exposing well "to the right" on the histogram, blending exposures to preserve blown highlights, or using an electronic shutter avoids banding entirely with Olympus cameras.

Of course, no lens or camera is a jack-of-all-trades, so we must each decide what will meet our needs. I love that this forum can help a lot with that.

EDIT: It seems to me also that there is no non-cosmetic difference between the original and Mark 2 versions of these lenses. Any perceived or reported differences might simply be due to sample variation.