I have a Janome 6600 too. I always have issues like this with FMQ. if i get the tension right on 90% of the stitches I still have eye-lashing on 10%. The thread (no matter what I use) will shred a few times during the process. The metallic thread needle is a good idea. It does seem to help. If you have any fused pieces in your quilt, my machine will always skip stitches over them. These are just a few reasons I am not sure I would ever buy another Janome machine.