I have the Panasonic 12-35 and 35-100 and am loving both. Very high quality and fantastic IQ. I would love a longer lens for vacations and am looking at the above two lenses. Does anyone have any comparisons, or know of any real world comparisons, between these lenses? I know there is quite a price difference. The Panasonic can be had for $399 used or $499 new, while the Olympus can be had for $600-$650 used and almost $900 new. Thanks ahead of time for any help.