What was the body they used?In the DPR video, the 12-45 was compared with the Panny 12-35 2.8. Their conclusion was that the Oly was a bit sharper. The other obvious differences were that the Oly focused closer and had more reach but the Panny was faster. Almost exactly the same size, so we get a real choice here.
To me, focusing speed & accuracy is as important as ultimate sharpness (if not more).