Since I've set up my table with the Mint, I have very centered imaging. I have been in the live recording studio, and attest that singers are in a booth. Their performance is carried on an individual track and in the mix, is positioned in the center of the orchestra. If your image is moving around, it's a fault and I would look at your setup. You say the Grado is the biggest culprit..probably the Grado is off "perfection" the most.
