Tim..... I'm being very picky but I have the right to be if I'm using my money...... as an example I don't even own an Otus any more - and I had three copies.
I see some smearing on the right hand side at maybe the 2/3 point..... but throughout the right side as compared to the left. At f5.6 I expect the lens to be close to perfect when photographing planar subjects. I don't believe the issue has anything to do with curvature. Again..... this is just me. Oddly I've been very critical of my Leica Summicron 50mm which has horrendous focus shift issues and is not as sharp as the Sony 55mm but it is very, very even from left to right.... not even a hint of decentering. I find that a real accomplishment since I can get around the focus shifting and can easily post process for sharpness issues. However, that's not where I would look for an alternative....
Again..... thanks so much for taking the time to post.
Victor