I did a brick wall test, and I think mine has decentering defects
The center is sharp, the left side is soft, but the right side is softer... I know there will will be corner softness, but both corners aren't the same, with the right side showing extreme softness...
I was initially fine with my copy's output, but after taking portraits, I found that people on the right side always looked soft. So I did the test. Is this reason enough for me to have it replaced or repaired?
edit: BTW, this is only one of many shots, all shots had the right side being soft. Parallel to the wall as well. Tried it with the 50-135, to see if maybe I wasn't parallel, the 50-135 was sharp across the frame...