Regarding the feed dog settings for finer and coarser fabrics; I have thought about them like an additional way to adjust pressure on the fabric, between feed dogs and presser foot. Especially the Japanese machines have this feature, and it's like a quick way to ajust presser foot tension, you have three preset options in a knob. The feed dogs move a bit lower for silk and rise a bit higher for heavier fabrics. I can sew silk chiffon and jersey pretty well on my model 99, it doesn't have any extra feature like this, it's as simple and basic as it gets. Does anyone get any use of this feature?