This is by no means an exhaustive fest, but I'm sure some other NEX and A6000 are curious what an extra $700 gets you. At the moment I happen to have both lenses in my possession and figured a quick test was in order. Both lenses make quite nice portrait lenses on aps-c with the Sony Zeiss 55mm being a touch longer and more ideal in the ~90mm equivalent range. In fact they are the only two true auto focusing portrait lenses for E mount cameras. I leave out the Sigma 60mm f/2.8 because of the slow aperture.

These images were shot back to back on a tripod with remote release and fast enough shutter to stop slight motion (1/320). White balance was set to cloudy because it was cloudy. Shot on a Sony A6000. Mouse over to compare images.