A very good lens but not without flaws
Bought this lens for use on my EM1 and GX7.
The lens is very sharp thoughout its range and foucuses fast.
Its makes a noise as if something was loose inside when the camera is off or the lens is unmounted. Turn the camera on and the noise goes away. Does not seen to interfere with function.
The barrel is smooth and makes manual focusung awkward. It is slippery.
The lens cap is outstanding as it does not slip out of your fingers as most can. It goes on and off easily even when the hood is on.
Optically it is outstanding. If you can live with the noise and slippery barrel it is a great lens at a bargain price.