The C above middle C may have a partial that's slightly too low in volume (or another that's too high) and\or may have a little less hammer sound in it. It seems a little hollow compared to the notes around it. The dreaded synthy tone at times at low to middle velocities.
Or is this just me?
It's probably not you, but it could be your monitors, headphones etc. I don't notice the problem with the C you speak of, either through my monitors or several different sets of phones. Mine sounds well balanced.
I tend to hear it as hollowish if I make fairly large edits. The notes on both sides come out fine, but somehow it stands out as having a little less body\force at low velocities. As you say, it may well be my headphones\monitors. That's why I posted--to see if it was just me. Thanks.