Zuiko 12-60mm f/2.8 lens on a OM-D Camera

I am interested in hearing whether anybody out there uses a 12-60mm Zuiko lens on their OM -D camera and what their experiences are?

I have recently been trying out the 14-54mm, f/2.8 and found it to be a fast, versatile and well balanced. It has super fast AF, sharp focus and exudes quality. I acknowledge that it is big and heavy but nonetheless it is very comfortable in the hand.

I have thought about the equivalent m4/3 lens but I am leaning towards the Zuiko 4/3.

All views would be appreciated.