IQ of Panasonic 14-45 f3.5-5.6 vs. Panasonic 12-35 f2.8

Can't agree more. And I never consider 14-45 good for two reasons: 1) It's not special. It's questionable if there is significant advantage of mirrorless camera with this lens over high end compact camera with larger aperture and good lens. 2) Mine is not sharp at more used wider end, but it seems that this is not a problem of this lens in general.

By the way, here is an excellent review (i just think that OIS is underestimated here):

http://cameraergonomics.blogspot.com/2012/12/lens-test-panasonic-lumix-gx-12-35mm.html