After reading and seeing so much great stuff about the Oly 17, I decided to trade my Panny 20mm for it. I loved the Panny's sharpness, but since I used it mostly indoors for family events, te slow AF caused me many missed pictures. I had hoped that the much faster Oly lens would suit my needs better. I was lucky to get a used copy at an OK price. To my shock, the images taken with the G3+Oly 17 combo turned out soft unless I had stopped the lens down to at least f3.5. And manual focussing didn't help either. Everything below that or - heaven forbid - at a wide open aperture was downright blurry. Being back home again, I took the lens to my camera dealer and asked him to check what was wrong (I was starting to seriously doubt my own abilities at this point). Turns out the lens takes perfect photos even wide open - just not with my G3. On the E-PL5 it's fine. They tested different lenses on my G3 and this Oly was the only one that didn't perform wide open. I didn't saw any reports about this anywhere so I'm wondering why this is? I have an Oly 9-18 and it's working fine on the G3. Very strange. If I wouldn't have decided to get an E-PL5 due to other reasons, I'd be pretty frustrated right now.