Surprised by the Panny 45-175mm power zoom - initial observations

From my experience this "double edge blur" is not the lens' fault. I saw it with 14-42PZ on GX1, and with 45-175PZ on GX1, but when I bought OM-D, there are no problems with 45-175! (I'm quite sure 14-42PZ would behave better with OM-D too, but I don't have it anymore). Do I have to mention that OM-D has much softer shutter? As well as 1/8s anti-shock delay...