The information I've seen reports that it only occurs when used wide open. I agree that it isn't evident in any of the photos, which is why I asked if people were correcting it in post, or if the early reviews were too harsh. Thanks for the response, it doesn't appear to be an issue.
Wide open until f4, I see slight colour fringing on blown highlights if viewed at 100%... on an Oly EM1X... I have seen a lot worse and the sharpness of the lens is so good that the fringing does not worry me.