I had bought the lens end in July 2013 just before a holiday in Croatia (at a local photo retailer - not here at Amazon) - as a promotional merchandise along with a Panasonic GX1. I had only a few days before the holiday to try out, and I did so intense. Of course, the camera was new, so I once had to cope with the settings.
I thought so, I was very spoiled by my Nikon D700 with the expensive 24-70 f / 2.8 and a considerable collection of prime lenses until I then two days before the holiday out of sheer desperation (the D700 was too large and too unwieldy for this holiday) nor the Panasonic had bought 20 f / 1.7 - and suddenly all the images were sharp. So it was not simply so that I had been too stupid or the camera was set incorrectly; this lens is traceable to blame.
When browsing in the internet (eg dpreview.com), you come to many others who have the same problem: This lens makes the GX1 (at other cameras that's probably better) just blurred images; namely no matter how you set the image stabilizer, if you screw the camera on a tripod, how to adjust the exposure time or whatever.
I am so very upset about this thing that I've just cleared unnoticed in the farthest corner of the cabinet for photo stuff (almost it would have ruined the holiday), but every time I somewhere on the web stumble back over this thing, foams I rage. The holiday has saved the Panasonic 20 f / 1.7; this lens is simply a piece of gold. The PZ 14-42, however, it is only worth that makes a high-resolution lens out of it - a 10,000-piece puzzle. With a sledgehammer namely.
I would have sold here on Amazon, if not, the process to be so horribly awkward and Amazon would not tuck in so outrageous there.
