I have printed a few small objects in vase mode with S3D seemed fine. I went to print some thing a little larger and I started to notice some jerky motion. When I speed up the motion, the jerking get worse, which can been see in the video (not terribly fast mind you) The hesitations ruin the print and it seems both X and Y are jerking at the same time. Slicing the same object in Slic3r I ramped up the Feed rate to 300 percent and dont seem to see the issue (other issues with that make not possible to print with slic3r currently but working on it.) Any ideas what might be happening? I am currently running RC5 firmware from @Alex9779 as well as a tweeked version of his S3D set up for vase mode. Tommorow will try the RC3 firmware.