Hi, posted my review a while ago and thought i'd give a short video of what i meant by drifting. In the video you'll see the cursor moving, however while the cursor is moving the mouse is not. This happens randomly sometimes more often than not. Sometimes it will also move faster than others...
It seems like all of the issues with it are ones that should have been easily spotted in QC. Personally the Twin-Eye's issue ( moving down/right when lifted) doesn't really affect me as i don't lift my mouse that much. The moving while clicking was 'fixed' by loosening the thumb-rest. However...