Considering the older Mark 1 does not have this issue, I don't think I'm being unreasonable in expecting better or at the very least the same level of performance considering the price and the fact that they have barely updated this lens besides painting it black. Except for the micro jitters, the mark 1 does quite well on the gimbal and I use it frequently without other complaints.   The 12-35 also worked pretty well and no complaints there...  Don't think I'm being unreasonable