Keep the Oly 17mm 1.8 or the Panasonic 20mm 1.7?

The 17mm does render some things more clearly than the 20mm, I guess that's what they mean by micro-contrast.  When I shoot against the sun, edges don't get eaten up by the light as much (I don't understand lens design enough to know how this is possible--is is flare resistance?).  It's still not getting more resolution data though.
The 17 is more consistent across the frame in terms of detail (even if it is softer), so general sharpening, as opposed to localized sharpening works without problems.

The 20mm can use some sharpening in the corners, but realistically, rarely needs any sharpening; on the contrary, if you add any significant image sharpening, images quickly look artificial and over-processed, particularly in the center.  Ocean waves I've noticed in particular look strange and prickly when I use a wrong image preset in LR4.