I read this with interest...I have a janome 6600 and Pfaff and have been FMQ for a few months...so very much a novice although do Calligraphy so think it might help a bit....had terrible issues with tension on the 6600 and some kind person suggested leaving the feed dogs up and stitch size at around three , suggesting this would sort out the tension problem and increase stitch regulation.
All I can say is I am amazed at the transformation in the quality of stitches....really regular, no skipping or eyelashes. I tend to set the speed between middle and top and use the start button so no foot pedal....as I've said amazing!